The phrase "gat the wagon" is an old-fashioned way of saying "get the wagon" in some dialects. The unusual spelling of "gat" is due to the presence of the phoneme /æ/ instead of the more common /ɛ/ in "get". This /æ/ sound is typically spelled with the letter "a" rather than the letter "e". The transcription for "gat" would be /ɡæt/, while "get" would be /ɡɛt/. In regular spelling, it would be more common to write "get the wagon".