......One afternoon last week, Coleman sat in a room she was renting for $230 a month in the suburbs of Columbia, Mo., with her new boyfriend. The old one hadn’t worked out, like so many things hadn’t worked out. She turned on her computer and opened a file of her photos from four years ago. Her boyfriend, Angad Mathur, had never seen them, and he sat down on the bed beside her. Together they began a 100-picture slide show of what she called “one of the most poignant, overwhelming nights of my life.” A photo of a crowded Grant Park...