An overwhelming majority of these groups were all male.

But sometimes you’ve got the option to espy a single woman sneaking in from behind.

When American documentary filmmaker Immy Humes trawled through the archives, she felt like playing Wheres Waldo?.

Medical student Anna Searcy in 1897

Can you spot the woman in these photographs?

Artist Hedda Sterne in 1951

Anti-imperialist Geraldine “Dinah” Stock, circa 1945

Unknown nurse in Boston, Massachusetts, 1890

Katharine Graham, publisher of the Washington Post, in 1975

Martha Gellhorn, War Correspondent, Cassino, Italy, 1944

Benazir Bhutto, Politician, Pakistan, 1988

Graciela, a pioneering Afro-Cuban jazz singer, at a concert in New York, New York, US, 1947

Gloria Richardson, Civil-rights leaders meet with Robert F. Kennedy, Washington, D.C., 1963

Mia Westerlund Roosen. Artists celebrate the 25th anniversary of the Leo Castelli Gallery, New York City, 1982

Lisette Dammas, jury for the espionage trial of Julius and Ethel Rosenberg, New York City, 1951

Lil Hardin, musician and songwriter, in Chicago, USA, 1923

Marie Curie, physicist and chemist, in Brussels, Belgium, 1911

Athlete Kathrine Switzer in 1967

Actress Marlene Dietrich in Europe in 1945

Peruvian journalist Angela Ramos in 1929

Civil rights leader Gloria Richardson in Cambridge, Maryland, 1963

Boxing promoter Florence North in 1922