Shortly after the bombing of Pearl Harbor, the U.S. began rounding up tens of thousands of Japanese Americans. They were sent to concentration camps in the western U.S. For nearly four years, men, women and children spent their lives enclosed behind barbed wire, watched by armed guards in towers. President Franklin D. Roosevelt and those who supported his executive order that paved the way for the camps said they were a military necessity. It was, after all, a time of war. But today many consider it to be one of the most shameful periods in American history. We look at how internment camps affected the lives of Japanese Americans for generations.