“I suffered evils,” said the African-American photographer Gordon Parks, “but without allowing them to rob me of the freedom to expand.” Parks’s imagery—much of it taken from the 1940s to the 1970s—documented the Civil Rights Movement with power and eloquence. Today, an Instagram account looks back at his candid shots and the moments they captured, comparing them to images from the present day. The tragedy and triumphs portrayed by Parks will resonate. —E.C.