。
She left Tokyo for New York yesterday.
Literal
She [topic-は] yesterday Tokyo [from-を] departing New-York [toward-へ] headed.
Two complementary directional particles split the work here: を marks Tokyo as the departure point (発つ 'to depart' takes its origin with を), while へ marks New York as the destination of motion. The te-form 発って sequences the two clauses ('left Tokyo and headed for New York'), letting the sentence trace the trip from origin to destination in one breath. 発つ is a less common kanji choice for たつ, specialized for departures on journeys; in everyday writing it's often replaced by 立つ or simply spelled in kana.