What was Jasper Cullen in the army?

Jasper Whitlock was a sargent major, the youngest one ever in the south because he lied about his age, highly talented, it was at the time of the Southern vampire wars where they fought against humans. He was changed in 1863 aged 19 by Maria, a vampire trying to create an evil army of newborns, she became his love intrest and played him, his love was never returned by her, though she pretended it was. Then eventually he met Alice after she saw him in a vision, and then they joined the Cullens and they became like they are now.