Complex sentence: A little more than a week later, on the 12, members of the 35th, attending a party in Hillsboro were surprised by the Loudoun Rangers, leaving 1 dead and 2 captured.
Split into simpler sentences: A little more than a week later, on the 12th, members of the 35th were attending a party in Hillsboro. They were surprised by the Loudoun Rangers, leaving 1 dead and 2 captured.