Complex sentence: All 508 tickets were sold out, with most tickets snapped up by the rich and important, but the ship nonetheless loaded 1,500 passengers fleeing their war-torn hometowns at the end of the Chinese Civil War.
Split into simpler sentences: All 508 tickets were sold out, with most tickets snapped up by the rich and important. But the ship nonetheless loaded 1,500 passengers on board fleeing their war-torn hometowns at the end of the Chinese Civil War.