Capitol Police officers will begin wearing special commemorative badges today to mark the law-enforcement agency’s 175th anniversary.

The badges, which will be worn in place of officers’ standard identification for the month of May, feature a replica of the star worn by Capitol Police officers at the turn of the century.

Additionally, a formal ceremony honoring the anniversary will be held at 10 a.m. Friday in Room G-50 of the Dirksen Senate Office Building.

Chief Terrance Gainer is scheduled to speak at the event, which will be emceed by Dave McConnell, WTOP radio’s Capitol Hill correspondent.

Capitol Police spokeswoman Jessica Gissubel said the National Archives has agreed to loan the original document which created the law-enforcement agency for display at the ceremony. The paper, dated May 2, 1828, bears the signature of then-President John Quincy Adams.

Additionally, House Administration Chairman Bob Ney (R-Ohio) will present Gainer with H. Con. Res 156, which honors both the anniversary and daily service of the Capitol Police force. The resolution is co-sponsored by ranking member John Larson (D-Conn.).

“From its humble beginnings until today, the Capitol Police has remained true to its mission, and has grown to meet new challenges and responsibilities,” Ney said on the House floor Tuesday.

Capitol Police Inspector Greg Parman, who heads the 175th anniversary committee, said the ceremony will be “an acknowledgement of the history and role of the Capitol Police in the protection of the Congress and the buildings here.”

Also expected to attend the event are members of the Capitol Police Board and former Chief James Varey.

An anniversary picnic for officers and their families is scheduled for June 21 at Bolling Air Force Base.