Complex sentence: The State Government did not return to Little Rock until the "Pontchartrain" arrived and a week later Hindman arrived to take command from Roane, and ordered all troops at Pine Bluff to Little Rock.
Split into simpler sentences: The state government did not return to Little Rock until the "Pontchartrain" arrived. A week later Hindman arrived to take command from Roane and ordered all troops in Pine Bluff to Little Rock.