Company lists · Data refreshed September 2026
Top 25 Constituent relations firms based in the United States
RevenueBase identified 752 constituent relations firms headquartered in the United States as of September 2026 and tracks 6,907 professional contacts across them, including 3,076 with verified work emails. Washington is the largest hub.
This list covers constituent relations firms headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 19, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.
The 25 largest constituent relations firms based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 390 contacts → | ||||
Partial evidence “Mercury is a national bipartisan government relations and strategic communications firm.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 2 | 349 contacts → | ||||
Partial evidence “DKC is a full service public relations, marketing and government affairs firm and part of the Acceleration Community of Companies, Based in New York City, and with offices in Los…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 3 | 255 contacts → | ||||
Partial evidence “Cornerstone Government Affairs is a full-service, bipartisan, employee-owned firm specializing in government relations and lobbying, public affairs, strategic communications, and…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 4 | 220 contacts → | ||||
Partial evidence “SKDK provides strategic advice, public relations, crisis communications, advertising, direct mail, and research to national and international companies, advocacy organizations…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 5 | 179 contacts → | ||||
Indirect evidence “Global Strategy Group is the go-to public affairs, communications, and research partner for companies, causes, and campaigns.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 6 | 166 contacts → | ||||
Indirect evidence “Invariant is a bipartisan business advisory firm, providing strategic advice to companies, trade associations, non-profits, and individuals on how to make Washington work for them.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 7 | 97 contacts → | ||||
Partial evidence “Monument Advocacy is a bipartisan firm that offers government relations, public affairs, strategic and crisis communications, and digital services.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 8 | 96 contacts → | ||||
Partial evidence “Justice Works Youth Care is a Government Relations company located in 615 Virginia Ave, Rochester, Pennsylvania, United States.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 9 | 84 contacts → | ||||
Indirect evidence “Founded in 1982, The Ferguson Group has a proud record of success advocating on behalf of local communities.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 10 | 72 contacts → | ||||
Partial evidence “Larson Shannahan Slifka Group (LS2group) is a bipartisan public relations, public affairs, and marketing firm that guides its practices with one goal in mind: what others may do…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 11 | 66 contacts → | ||||
Indirect evidence “Bose Public Affairs Group successfully advocates for our clients’ legislative, regulatory, procurement, political and communication interests with offices in Indianapolis and…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 12 | 63 contacts → | ||||
Partial evidence “Capitol Counsel, LLC is a full service government relations firm providing political analysis, strategic advice and advocacy services.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 13 | 57 contacts → | ||||
Indirect evidence “We are innovators and thought leaders who believe in developing robust integrated solutions for our clients.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 14 | 55 contacts → | ||||
Indirect evidence “At Beekeeper Group we believe in empowering people to advocate for impact by connecting them with stakeholders that are ready to take action so that our clients can achieve their…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 15 | 53 contacts → | ||||
Indirect evidence “Smart strategy begins with being well informed.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 16 | 53 contacts → | ||||
Partial evidence “TRG is a government relations consulting firm located on the doorstep of the United States Capitol.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 17 | 43 contacts → | ||||
Partial evidence “The Livingston Group (TLG) has delivered comprehensive government relations and lobbying services in Washington DC and globally since With nine different practice areas, our…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 18 | 40 contacts → | ||||
Partial evidence “S-3 is a full service policy and government relations firm providing comprehensive solutions in government affairs and public relations to top tier clients whose priorities demand…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 19 | 37 contacts → | ||||
Partial evidence “Crossroads Strategies, LLC (CRS) is a bipartisan, multi-disciplinary federal relations, advocacy, and advisory firm based in Washington DC.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 20 | 36 contacts → | ||||
Partial evidence “Brown & Weinraub, PLLC is a leading edge Government Relations & Strategic Consulting firm, representing a broad spectrum of business interests established and/or seeking to expand…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 21 | 35 contacts → | ||||
Partial evidence “Tiber Creek Group is a premier, bipartisan government relations firm delivering custom policy solutions and strategies for industry leaders.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 22 | 33 contacts → | ||||
Indirect evidence “Englander Knabe & Allen (EKA) is a strategic communications firm specializing in government affairs, political campaigns, reputation and crisis communications, association…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 23 | 33 contacts → | ||||
Indirect evidence “We provide a powerful strategic advantage to our clients as they compete for market share, expansion, and profitability in today's ever-changing political landscape.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 24 | 31 contacts → | ||||
Indirect evidence “Our mission is to ensure that the right people know the right thing about your issue.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 25 | 30 contacts → | ||||
Partial evidence “AxAdvocacy is a leading public affairs and government relations firm dedicated to navigating the complex landscape of public policy and advocacy.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: constituent relations firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names constituent relations firms.
- Partial evidence
- Its own public description names part of constituent relations firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name constituent relations firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 25 of 752 constituent relations firms based in the United States
See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 3,076 reachable decision-makers.
Free signup · no credit card
Constituent relations firms based in the United States at a glance
As of Sep 19, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 752 companies.
How this list was built
Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among constituent relations firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.
- Source
- The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
- What qualifies
- Companies headquartered in the United States whose own description of what they do matches “constituent relations firms”. Matching reads each company's description, not its industry code or its name.
- RevenueBase Smart Search
- RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names constituent relations firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
- What we exclude
- Companies whose own description does not clearly place them among constituent relations firms, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
- Match quality
- In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
- Ranking
- Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
- Verification
- Every listed company carries at least one verified work email, 3,076 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
- Refresh
- This page's figures were pulled from the company graph on September 19, 2026. Lists refresh periodically as the graph is re-checked.
- Corrections
- Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.
Constituent relations firms by metro
- Constituent relations firms in Washington146
Frequently asked
What is RevenueBase Smart Search?
RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names constituent relations firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.
How many constituent relations firms are there based in the United States?
RevenueBase identified 752 constituent relations firms headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.
What is the largest company on this list?
Mercury Public Affairs, LLC, headquartered in New York, tops this list with the largest team on record.
Which city has the most constituent relations firms?
Washington leads with 146 headquartered companies, followed by Sacramento (22) and New York (20).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 3,076 verified decision-maker contacts tracked across these 752 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 19, 2026.
Ready to reach these companies? Verified emails and direct dials for all 752 constituent relations firms based in the United States. Start with a free account, no credit card.
Download this list →Related lists
Constituent relations firms by geography
About this data
RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.
More company lists
- All company lists
- Lists by location
- Lists A-Z
- New lists
- Constituent relations firms based in Canada
- AI companies based in the United States
- Cybersecurity companies based in the United States
- Manufacturing companies based in the United States
- Media companies based in the United States
- Oil and gas companies based in the United States