After the unsuccessful attempt to capture Savannah, Georgia, under the command of General Benjamin Lincoln, the Southern Department of the Continental Army retreated to Charleston, South Carolina. General Sir Henry Clinton moved his forces, surrounded the city where Lincoln's army was located and cut off any chance of relief for the Continental Army. Prior to his surrender, Lincoln had been able to get messages to General Washington and Congress requesting aid. At the end of April 1780, Washington dispatched General Johann de Kalb with 1,400 Maryland and Delaware troops. The Maryland Line made up a large portion of this force, with Williams serving in the post of Adjutant general to General De Kalb.