As per your request here I am providing you the list of Public Affairs Consulting Firms which is located in Washington DC also providing you the address of those firms:

Public Affairs Consulting Firms Washington DC:

Howard Consulting Group, Inc.
1990 M St NW #310
+1 202-429-4390

Qorvis Communications – PR, Advertising, Public Affairs, Research & Web Design
1201 Connecticut Ave NW #500
+1 202-496-1000

SevenTwenty Strategies
1220 19th St NW #300
+1 202-962-3955

FleishmanHillard Washington, D.C.
1615 L St NW #1000
+1 202-659-0330

Fleishman-Hillard Inc
2815 N St SE
+1 202-828-9771

Mercury Public Affairs
701 8th St NW #650
+1 202-551-1440

Mercury Public Affairs
601 Pennsylvania Ave NW
+1 202-551-1440

Public Strategies Inc
607 14th St NW
+1 202-628-0697

Berlinrosen Public Affairs
1776 Massachusetts Ave NW
+1 202-560-5990

LEVICK
1900 M St NW #400
+1 202-973-1300

Edelman
1875 I St NW #900
+1 202-371-0200

kglobal
2001 L St NW
+1 202-349-7075

SKDKnickerbocker
1150 18th St NW #800
+1 202-464-6900

Amplify Public Affairs
1750 K St NW #7
+1 202-293-4444

Sphere Consulting
1775 I St NW #410
+1 202-862-5520

APCO Worldwide - Global Headquarters
700 12th St NW #800
+1 202-778-1000

Prism Public Affairs
1399 New York Ave NW #550
+1 202-575-3800

Global Strategy Group
1001 G St NW
+1 202-525-4125

Peter Mirijanian Public Affrs
2445 M St NW #2
+1 202-464-8803

Purple Strategies
815 Slaters Ln
+1 703-548-7877