Pacific Standard Time: Art in L.A., 1945–1980

John Riddle, Ghetto Merchant, 1966
The work of African-American artists in Los Angeles often had a political subtext. The principal element of Riddle's welded-steel-assemblage sculpture is the melted remains of a cash register dug from the embers of the 1965 Watts riots.

At the Hammer Museum

• California's Changing Landscape