More than four decades of 20th-century America are filtered through Lange's life and lens-her creations and achievements, her tragedies and losses. Known for her powerful images from the Great Depression, her haunting "Migrant Mother" remains emblematic of that period. In 1936, when photographs of the poverty-stricken mother of seven, stranded in a camp in California, were published, a national awareness began. As America matured into a world power,...