Soldiers will place more than 200,000 flags on graves at Arlington National Cemetery Thursday.
The 3rd U.S. Infantry, also known as "The Old Guard," performs the "flags in" ceremony each year before Memorial Day weekend.
The flags will be removed after Memorial Day.
A similar ceremony will take place on the National Mall Thursday morning. Soldiers with the U.S. Army Corps of Engineers will lay wreaths at all three war memorials.
The soldiers will march 24 miles from Fort Belvoir to the National Mall, arriving at the Korean War Memorial around 11:15 a.m. From there, they'll head to the Vietnam Memorial before ending at the World War II Memorial.
For more information on Memeorial Day weekend events in the D.C. area, click here.
The Old Guard was established in 1784 and is the oldest infantry regiment in the country. Its main duties are to lead memorial affairs for fallen soliders and, according to its website, "[conduct] special events to represent the Army, communicating its story to our Nation's citizens and the world."
Soldiers in The Old Guard also serve as watchmen at the Tomb of the Unknown Soldier at the Arlington National Cemetery.
The Old Guard Association was created in 1997 to connect past and present members of the 3rd U.S. Infantry. It currently has 895 members and has held 14 reunions.