Slavin has written: "Few people outside of Portugal knew the power being wielded on the Iberian Peninsula during the early 1930s to late 1960s.
I lived and photographed the Portuguese people from late 1967 to 1968, when Salazar’s health took an unexpected turn for the worse, ending his dictatorship."
Britons is a series of photographs of people from Britain, commissioned by the National Museum of Photography, Film and Television in the UK.
He was also awarded the 1988 Augustus Saint-Gaudens Medal and the 2005 President's Citation by his alma mater, the Cooper Union.
In 1994, he ceased his commercial work to devote all his time to developing, directing and producing a film entitled Focus, based on Arthur Miller’s only novel, about prejudice and race in America in the early 1940s.