Growing up in Westminster in northern Maryland, Ron Shriver, 29, used to pass by the stately brick buildings of the college that is now McDaniel College and wonder: What went on up there on that hill overlooking Main Street? What would it be like to go to a college like that? What would it be like to go to college at all? Nobody in Mr. Shriver's family had ever done so, and for a long time, it looked as if he wouldn't, either. The oldest of four sons, he left home at 17. He had tired of clashing with his father, a strong-willed brick mason, and went to work nights at a local grocery store to support himself while he finished high school. During his senior year, he enlisted in the U.S. Marine Corps under a delayed-entry program. He reported for basic training in August 2001. In the service, he earned a top-secret security clearance and elite postings as a military police officer, first with the squadron that accompanies the president on his travels, then handling personal security for the commander of the U.S. Pacific Command. He married a fellow Marine, and they had two children. Mr. Shriver thought he had found his career and his life. He had been promoted regularly, reaching the rank of staff sergeant in an unusually short seven years. In Virginia and Hawaii, where he was stationed during his military career, the family purchased and renovated two homes. During those years, he completed 10 general-education courses online. His goal was to earn an associate degree. But when word came that Congress was considering a new version of the GI Bill that would allow veterans to attend college full time and have their living expenses covered, both Mr. Shriver and his wife, Jennifer--who had also joined the Marines straight out of high school, in California--paid attention. In June 2008, the Post-9/11 GI Bill passed. All at once, a path Mr. Shriver had thought impossible opened up. He could get an education. He could explore careers beyond the military and law enforcement. And he could teach his children about determination. On May 19, Mr. Shriver graduated from McDaniel. His journey, of course, is just one among those of half a million veterans who've enrolled in college under the Post-9/11 GI Bill. But his hopes are emblematic of the promise the federal program has inspired.