WATCH LIVE: Harvey Milk Stamp Dedication

Politicians, activists, and LGBT notables will attend a special event at the White House Thursday to officially dedicate the Harvey Milk Stamp at 3 p.m. Eastern time.

Expected attendees include U.S. Ambassador to the United Nations Samantha Power, House Democratic Leader Nancy Pelosi, Senator Tammy Baldwin, Representative John Lewis, Deputy Postmaster General Ronald A. Stroman, and other distinguished guests including the Co-Founders of the Harvey Milk Foundation, Stuart Milk and Anne Kronenberg.

Watch the event live here:

The U.S. Postal Service will release a forever stamp honoring the late LGBT political icon Harvey Milk. The stamp ceremony will take place May 22 at the White House, and a special dedication ceremony will take place May 28 in San Francisco, the U.S. Postal Service announced Monday.

The stamp is based on a famous photo of Milk, taken in 1977 by Daniel Nicoletta in front of Milk's shop, Castro Camera. It was designed by Antonio Alcala of Alexandria, Va.

After only a short time in political office, Milk's activism charged a generation of people in the march toward LGBT rights. In 1978, he and Mayor George Moscone were assassinated. In 2009, Milk was posthumously awarded the Medal of Freedom by President Barack Obama.

Milk's stamp joins other civil rights revolutionaries and politicians, including Rosa Parks and Rep. Shirley Chisholm.