George Rogers Clark arrived at Fort Massac on June 30, 1778, with about 175 men under orders from Virginia to capture the British outposts in Illinois. British failure to regarrison the old French fort there enabled Clark to enter the Illinois country without opposition. Expecting an attack from the Mississippi River, the British at Kaskaskia were surprised when Clark marched overland. He arrived at Kaskaskia on the night of July 4-5 and quickly secured the fort without resistance.