Sarah Greenough, senior curator and head of the department of photographs, National Gallery of Art. In celebration of the exhibition opening, curator Sarah Greenough introduces Harry Callahan at 100 on view at the National Gallery of Art from October 2, 2011, through March 4, 2012. As Greenough notes, this exhibition celebrates the 100th anniversary of Callahan's birth in 1912. The exhibition explores all facets of Callahan's rich contribution to 20th-century American art from his earliest work made in Detroit during World War II, to photographs made in Chicago in the late 1940s and 1950s, to works made in Providence in the 1960s and 1970s, to his final pieces made during travels around the world in the later 1970s, 1980s, and 1990s.