A Philadelphia activist donates to the Smithsonian's Nat'l Museum of American History.

WASHINGTON, D.C. (WPVI) -- An activist, journalist, civil rights pioneer and national LGBTQ leader from Philadelphia made a massive donation to the Smithsonian's National Museum of American History Thursday.

Mark Segal has documented his activism efforts for nearly 50 years.

He donated rare journals, flyers, posters, letters and materials that from his career that cover the 1970s to the present.

Segal also donated artifacts from his personal collection, including the first state-issued Gay Pride Proclamation.