Complex sentence: By November 25, Gage was strong enough to return to his parents' home in Lebanon, New Hampshire, traveling there in a "close carriage" i.e. an enclosed carriage for transportation of the insane.
Split into simpler sentences: By November 25, Gage was strong enough to return to his parents' home in Lebanon, New Hampshire. He traveled in a "close carriage", which was an enclosed carriage for transportation of the insane.