When did Edgar Allan Poe change his name?

Poe never changed his name in the usual sense. He was born Edgar Poe, but after his parents died and he was taken in as a foster child by John and Frances Allan, they had him baptized as Edgar Allan Poe. As a young man he enlisted in the army under the name of Edgar Perry, but that was just given as a false name. Poe did not keep it after he left the aemy.