Gay Marriage Supporters Rally Against DOMA at Supreme Court on March 27, 2013 in Washington, DC (Footage by Getty Images)

Gay Marriage Supporters Rally Against DOMA at Supreme Court on March 27, 2013 in Washington, DC (Footage by Getty Images)

Gay Marriage Supporters Rally Against DOMA at Supreme Court on March 27, 2013 in Washington, DC (Footage by Getty Images)

Gay Marriage Supporters Rally Against DOMA at Supreme Court on March 27, 2013 in Washington, DC (Footage by Getty Images)

Gay Marriage Supporters Rally Against DOMA at Supreme Court on March 27, 2013 in Washington, DC (Footage by Getty Images)

Gay Marriage Supporters Rally Against DOMA at Supreme Court on March 27, 2013 in Washington, DC (Footage by Getty Images)

Gay Marriage Supporters Rally Against DOMA at Supreme Court on March 27, 2013 in Washington, DC (Footage by Getty Images)

Gay Marriage Supporters Rally Against DOMA at Supreme Court on March 27, 2013 in Washington, DC (Footage by Getty Images)

International flags on a background of blue sky

/ Washington Mall at dawn / aerials / train arriving into station, demonstrators disembark and sing 'We Shall not be Moved'. People arrive for the March on Washington on August 28, 1963 in Washington, DC (Footage by Getty Images)

/ Freedom Now Movement truck drives through city streets with sound system calling for people to attendance the March on Washington / organizers hand out leaflets. March on Washington organizers campaign for attend on January...

Gay rights activist rally in support of gay marriage March 25, 2013 in Chicago, Illinois. (Footage by Scott Olson/Getty Images) Activists Rally In Favor Of Same Sex Marriage In Chicago on March 25, 2013 in Chicago, Illinois (Footage by...

Gay rights activist rally in support of gay marriage March 25, 2013 in Chicago, Illinois. (Footage by Scott Olson/Getty Images) Activists Rally In Favor Of Same Sex Marriage In Chicago on March 25, 2013 in Chicago, Illinois (Footage by...

The Lincoln Memorial in Washington D.C.

Amma Asante on audience reaction at the 'Belle' premiere at BFI Southbank on 5 June, 2014 in London, England.

INTERVIEW - Sam Reid on the movie messages and Oprah Winfrey at the 'Belle' premiere at BFI Southbank on 5 June, 2014 in London, England.

/ men at microphone counting down to test the audio systems, Washington Monument in background / empty chairs / people on telephones, setting up bleachers. Organizers setting up for the March on Washington on August 27, 1963 in...

Gay Marriage Supporters Rally Against DOMA at Supreme Court on March 27, 2013 in Washington, DC (Footage by Getty Images)

28th August 1963, high angle PAN large crowd marching with signs on wide street / March on Washington / newsreel