The Grand Union Flag (also the Continental Colors, the Congress Flag, the Cambridge Flag, and the First Navy Ensign) is considered to be the first national flag of the United States. This flag consisted of thirteen red and white stripes with the British Union Flag of the time (the variant prior to the inclusion of the St. Patrick's cross of Ireland) in the canton.
By the end of 1775, during the first year of the American Revolutionary War, the Continental Congress operated as a de facto war government authorizing the creation of an army, navy and even a marine corps. A new flag was required to represent the Congress and fledgling nation, different from the Red Ensign flown from British vessels and British Union flags carried by the King's troops.
The Grand Union flag was first hoisted on the USS Alfred, in Philadelphia, Pennsylvania on December 3, 1775, by Lieutenant John Paul Jones. The event had been documented in letters to Congress and eyewitness accounts. The Grand Union flag was used by the American Continental forces as both a naval ensign and garrison flag through 1776 and early 1777.
It is not known for certain when, or by whom, the Continental Colors' design was created, though the flag could easily be produced by sewing white stripes onto the previous British Red Ensigns. The Alfred flag has been credited to Margaret Manny.
It was widely believed that the flag was raised by George Washington's army on New Year's Day 1776 at Prospect Hill in Charlestown (now part of Somerville), near his headquarters at Cambridge, Massachusetts, and that the flag was interpreted by British observers as a sign of surrender. Some scholars dispute this traditional account, concluding that the flag raised at Prospect Hill was probably a British union flag.
The name "Grand Union" is contemporary to Reconstruction-era historians, having been first applied to the Continental Colors by George Preble in his 1872 History of the American Flag.
The design of the Grand Union flag is similar to the flag of the British East India Company (EIC). Indeed, certain EIC designs in use since 1707 (when the canton was changed from the flag of England to that of Great Britain) were nearly identical, though the number of stripes varied from 9 to 15. That EIC flags were potentially well known by the American colonists has been the basis of a theory of the origin of the Grand Union flag's design.
The Flag Act of 1777 authorized a new official national flag of a design similar to that of the Colors, with thirteen stars (representing the thirteen States) on a field of blue replacing the British Union flag in the canton. The combined crosses in the Union flag symbolized the union of the kingdoms of England and Scotland; the symbolism of a union of equal parts was retained in the new American flag.