Complex sentence: Allen Guelzo grew up at his father's post assignments, from Fort Eustis, in Virginia, to the Presidio, in Monterey, California and spent his school years with his maternal grandparents in Springfield (Delaware county), Pennsylvania, a suburb of Philadelphia.
Split into simpler sentences: Allen Guelzo grew up in-and-around his father's post assignments, from Fort Eustis, in Virginia, to the Presidio, in Monterey, California. However, he spent his school years with his maternal grandparents in Springfield (Delaware county), Pennsylvania, a suburb of Philadelphia.