Company lists · Data refreshed September 2026

Top 25 Government investigations law firms based in Chicago, United States

RevenueBase identified 64 government investigations law firms headquartered in Chicago, United States as of September 2026 and tracks 8,280 professional contacts across them, including 4,621 with verified work emails. Across the United States, New York is the largest hub for this category (185 companies); Chicago has 64.

This list covers government investigations law firms headquartered in Chicago, 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 28, 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 28, 2026 86% judged on-target in blind review
64Companies
8,280Contacts tracked
4,621Verified emails
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The 25 largest government investigations law firms based in Chicago, United States

Ranked by team size
Top 25 of 64 government investigations law firms based in Chicago, United States, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to government investigations law firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceChicago, IL, United StatesHQ checked Sep 28, 20261,001-5,0002,167 contacts →

Indirect evidence

“High stakes.”

Source: RevenueBase Database · checked Sep 28, 2026
2Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 20261,001-5,0001,495 contacts →

Partial evidence

“Katten is a full-service law firm with nearly 650 attorneys in locations across the United States and in London and Shanghai.”

Source: RevenueBase Database · checked Sep 28, 2026
3Indirect evidenceChicago, IL, United StatesHQ checked Sep 28, 2026501-1,0001,194 contacts →

Indirect evidence

“At Jenner & Block, we shape what’s next through experience, vision, and judgment.”

Source: RevenueBase Database · checked Sep 28, 2026
4Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 2026501-1,0001,188 contacts →

Partial evidence

“Hinshaw & Culbertson LLP is a U.S-based law firm with offices nationwide.”

Source: RevenueBase Database · checked Sep 28, 2026
5Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 2026201-500353 contacts →

Partial evidence

“Neal Gerber Eisenberg is a Chicago-based law firm whose attorneys share a culture of teamwork and devotion to personalized client service to advance our clients’ business…”

Source: RevenueBase Database · checked Sep 28, 2026
6Strong evidenceChicago, IL, United StatesHQ checked Sep 28, 202651-200125 contacts →

Strong evidence

“EDELSON PC is a law firm concentrating on high-stake’s plaintiff’s work ranging from class and mass actions to public client investigations and prosecutions.”

Source: RevenueBase Database · checked Sep 28, 2026
7Indirect evidenceChicago, IL, United StatesHQ checked Sep 28, 202651-20069 contacts →

Indirect evidence

“We are a team of problem solvers.”

Source: RevenueBase Database · checked Sep 28, 2026
8Indirect evidenceChicago, IL, United StatesHQ checked Sep 28, 202651-20065 contacts →

Indirect evidence

“Eimer Stahl is a boutique commercial litigation firm headquartered in Chicago, with offices in Madison, Silicon Valley, San Francisco, and Nashville.”

Source: RevenueBase Database · checked Sep 28, 2026
9Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 202611-5053 contacts →

Partial evidence

“Christensen Hsu Sipes LLP is a law firm with offices in Chicago, Northwest Indiana, Los Angeles, and Sacramento.”

Source: RevenueBase Database · checked Sep 28, 2026
10Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 202611-5029 contacts →

Partial evidence

“A high-powered law firm for savvy companies, Massey & Gail offers creative solutions in counseling, litigation and appeals.”

Source: RevenueBase Database · checked Sep 28, 2026
11Indirect evidenceChicago, IL, United StatesHQ checked Sep 28, 202611-5029 contacts →

Indirect evidence

“Nathan & Kamionski LLP is dedicated to client service at the highest level of professional commitment and quality.”

Source: RevenueBase Database · checked Sep 28, 2026
12Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 202611-5028 contacts →

Partial evidence

“Founded in 1993 by several attorneys previously affiliated with a large Chicago law firm, Hogan Marren, Ltd.”

Source: RevenueBase Database · checked Sep 28, 2026
13Indirect evidenceChicago, IL, United StatesHQ checked Sep 28, 202611-5026 contacts →

Indirect evidence

“Strauss Borrelli PLLC is an innovative class action practice that seeks to challenge the relationship between individuals and corporations through impact litigation.”

Source: RevenueBase Database · checked Sep 28, 2026
14Indirect evidenceChicago, IL, United StatesHQ checked Sep 28, 20261-1026 contacts →

Indirect evidence

“As of July 2022, Shepard Schwartz & Harris LLP joined Citrin Cooperman.”

Source: RevenueBase Database · checked Sep 28, 2026
15Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 202611-5019 contacts →

Partial evidence

“The Sotos Law Firm focuses on representing public and private sector companies and officials.”

Source: RevenueBase Database · checked Sep 28, 2026
16Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 202611-5016 contacts →

Partial evidence

“Founded by a team of Big Law veterans, our firm blends the nimble entrepreneurialism of a boutique start-up with the wisdom and experience that comes from decades of deftly…”

Source: RevenueBase Database · checked Sep 28, 2026
17Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 202611-5015 contacts →

Partial evidence

“More than 25 years ago, six attorneys started a law firm which quickly developed a national reputation as a preeminent litigation law firm.”

Source: RevenueBase Database · checked Sep 28, 2026
18Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 202611-5013 contacts →

Partial evidence

“RK is a minority-certified firm that specializes in the dynamic intersection between business and government.”

Source: RevenueBase Database · checked Sep 28, 2026
19Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 20261-1011 contacts →

Partial evidence

“Gair Gallo Eberhard provides its clients with the hard-charging, strategic top-flight representation of the country’s elite law firms in white collar criminal defense and complex…”

Source: RevenueBase Database · checked Sep 28, 2026
20Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 202611-5010 contacts →

Partial evidence

“Chicago Law Partners, LLC is a boutique law firm focused primarily on representing trade associations, professional societies, foundations, other types of not-for-profit…”

Source: RevenueBase Database · checked Sep 28, 2026
21Indirect evidenceChicago, IL, United StatesHQ checked Sep 28, 202611-5010 contacts →

Indirect evidence

“Henderson Parks is a corporate litigation and trial boutique.”

Source: RevenueBase Database · checked Sep 28, 2026
22Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 20261-109 contacts →

Partial evidence

“Laduzinsky & Associates is a full-service law firm dedicated to providing legal services in a direct, efficient, and effective manner.”

Source: RevenueBase Database · checked Sep 28, 2026
23Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 20261-109 contacts →

Partial evidence

“Zigler Law Group is a national class action and complex litigation firm committed to protecting consumers and investors from corporate misconduct.”

Source: RevenueBase Database · checked Sep 28, 2026
24Indirect evidenceChicago, IL, United StatesHQ checked Sep 28, 20261-108 contacts →

Indirect evidence

“Polales Horton & Leonardi LLP is a firm of experienced courtroom advocates, founded on decades of success, focusing on white-collar criminal defense, business disputes, insurance…”

Source: RevenueBase Database · checked Sep 28, 2026
25Partial evidenceChicago, IL, United StatesHQ checked Sep 28, 20261-107 contacts →

Partial evidence

“Founded by professionals with decades of diverse experience conducting complex multi-jurisdictional investigations, 221B Partners finds the dots and connects them.”

Source: RevenueBase Database · checked Sep 28, 2026

Showing 25 of 64 government investigations law firms based in Chicago, United States

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Government investigations law firms based in Chicago, United States at a glance

As of Sep 28, 2026
55.8%Verified-email coverage
129.4Average contacts per company
1-10Median size (employees)
Sep 28, 2026Page data refreshed

Companies by employee count

1-10
38
11-50
14
51-200
4
201-500
3
501-1,000
2
1,001-5,000
3

Email recency for this list is measured across the whole United States list rather than for Chicago, so it is reported there. Company counts and contact totals on this page are exact for Chicago, over 64 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 government investigations law 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 Chicago, United States whose own description of what they do matches “government investigations law 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 government investigations law 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 government investigations law firms, and records with no verified work email. Companies headquartered outside Chicago 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, 4,621 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 28, 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.

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 government investigations law 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 government investigations law firms are there based in Chicago, United States?

RevenueBase identified 64 government investigations law firms headquartered in Chicago, 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?

Seyfarth Shaw LLP, headquartered in Chicago, tops this list with the largest team on record.

Which city in the United States has the most government investigations law firms?

New York leads the United States with 185 headquartered companies, followed by Washington (172) and Chicago (64).

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 4,621 verified decision-maker contacts tracked across these 64 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 28, 2026.

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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.