Since its official establishment on June 14, 1775, more than a year before the Declaration of Independence, the United States Army has played a vital role in the growth and development of the American nation. Drawing on both longstanding militia traditions and newly introduced professional standards, it won independence for the new republic during an arduous eight-year struggle against Britain. Sometimes the army provided the only symbol of the nation around which the patriots gathered.
On March 25, 1774, as a result of the Boston Tea Party, the British Parliament closed Boston Harbor to shipping with its passage of the Boston Port Act, which went into effect June 1, 1774. It was the first of the coercive acts , or Intolerable Acts, five laws passed by the British Parliament to suppress resistance to its authority over the American colonies.
Tensions escalated when Lieutenant General Thomas Gage, Commander-in-Chief of British Forces in North America and Royal Governor of the Massachusetts Bay Colony, invoked the new law in October 1774 and dissolved the provincial assembly. In response, the colonists formed their own alternative government—the Massachusetts Provincial Congress, which controlled the entire colony outside of Boston—and prepared for a possible military confrontation with the forces occupying the capital.
On learning that this extra-legal government was amassing stocks of arms at Concord, about 20 miles from Boston, Gage sent a military expedition on April 18, 1775 to seize and destroy any ordnance his men could find. This led to an exchange of musketry between local militia and British troops at the Village Green in Lexington and the Old North Bridge in Concord on 19 April 1775, signaling the start of the Revolutionary War.
Militia units and other volunteers from Massachusetts and other New England colonies soon converged on Cambridge. They formed what became known as the New England Army of Observation and besieged the British forces stationed in Boston. For now, the rebellion was a regional affair.
Now that the fighting had begun, the Massachusetts Provincial Congress turned to the Continental Congress, which met May 10 in Philadelphia, for help from the other 12 colonies in British America. After much discussion, the delegates decided to create an army that would represent not only New England, but all of the British colonies on the North American continent.
The next step was to select a commander-in-chief. George Washington of Virginia was the preferred choice because of his famous military record and the hope that a leader from Virginia could further unite the colonies. Congress voted unanimously on the measure and the next day presented its commission to Washington.
Thus, the Continental Congress appointed George Washington Commander-in-Chief of the Continental Army on June 19, 1775.
When Congress declared independence, the Continental Army and Congressional Service Militia became collectively known as the United States Army, instead of the United Colonies Army.