With hostilities underway, Hanson chaired the Frederick County Committee of Observation, part of the Patriot organization that assumed control of local governance. Responsible for recruiting and arming soldiers, Hanson proved to be an excellent organizer, and Frederick County sent the first southern troops to join George Washington's army. Because funds were scarce, Hanson frequently paid soldiers and others with his own money. In June 1776, Hanson chaired the Frederick County meeting that urged provincial leaders in Annapolis to instruct Maryland's delegates in the Continental Congress to declare independence from Great Britain. While Congress worked on the Declaration of Independence, Hanson was in Frederick County "making gunlocks, storing powder, guarding prisoners, raising money and troops, dealing with Tories, and doing the myriad other tasks which went with being chairman of the committee of observation".