American Public Education kept its prices close to the military's tuition assistance cap, which made it an easy choice for people in uniform. Its American Military University and American Public University offered degrees that soldiers, sailors and veterans could finish from anywhere. When it filed in 2007, for-profit online colleges were growing fast. APEI stood out for its low tuition and its military focus.

A Marine's Mobile Campus

James Etter, a retired Marine officer, founded American Military University in 1991. His bet was simple. Service members move often and deploy far from campus, so they needed a university that went with them. The school kept its admissions open and taught online. Military tuition assistance often paid for the degrees. Courses started every month, which suited students on shifting military schedules.

Nursing and Civilians

APEI priced its IPO at $20 a share in November 2007 on the Nasdaq, and the stock climbed in its early years. Enrollment later slowed as for-profit education faced tighter federal rules. The company expanded into nursing education through acquisitions. The American Public University System remains its core, and it now serves many civilian students alongside service members. APEI remains publicly traded on the Nasdaq.

Cover: A Mounted Officer, Jean Baptiste Édouard Detaille. Art Institute of Chicago, public domain. Chosen for a mounted officer (military students).