Complex sentence: When Tobias Trumball, Alicia's uncle, found her, he tried to take her home, which Judson prevented, after which Trumball challenged Judson to a duel and scheduled it for July 3,1776.
Split into simpler sentences: When Tobias Trumball, Alicia's uncle, found her, he tried to take her home, but Judson prevented him from doing that. So Trumball challenged Judson to a duel and scheduled it for July 3,1776.