Complex sentence: The rest of the fleet sailed on to Jamestown, delivering hundred of additional colonists, but little in the way of food, supplies, or leaders, all of which had been principally carried on the "Sea Venture".
Split into simpler sentences: The rest of the fleet sailed on to Jamestown, delivering hundreds of additional colonists. They had little in the way of food, supplies, or leaders, all of which had been principally carried on the "Sea Venture".