Gates has been described as "one of the Revolution's most controversial military figures" because of his role in the Conway Cabal, which attempted to discredit and replace General George Washington; the battle at Saratoga; and his actions during and after his defeat at Camden.

Shortly after Gates took charge of the Northern Department, the Continental Army defeated the British at the crucial Battles of Saratoga.

Dorothea Reeve was housekeeper for the second Duke of Leeds, Peregrine Osborne (died June 25, 1729), which in the social context of England at the time was a patronage plum.

Through Dorothea Gates's associations and energetic networking, young Horace Walpole was enlisted as Horatio's godfather and namesake.

He arrived in Halifax, Nova Scotia, under Edward Cornwallis and later was promoted to captain in the 45th Foot, under the command of Hugh Warburton, the following year.

This force included other future Revolutionary War leaders such as Thomas Gage, Charles Lee, Daniel Morgan, and George Washington.

When the word reached Gates of the outbreak of war in late May 1775, he rushed to Mount Vernon and offered his services to Washington.

[8] Gates spent the summer of 1776 overseeing the enlargement of the American fleet that would be needed to prevent the British from taking control of Lake Champlain.

The American fleet was defeated at the Battle of Valcour Island in October 1776, although the defense of the lake was sufficient to delay a British advance against Ticonderoga until 1777.

When Washington dismissed this advice, Gates claimed illness as an excuse not to join the nighttime attack and instead traveled on to Baltimore, where the Continental Congress was meeting.

Although Gates actively lobbied Congress for the appointment, Washington's stunning successes at Trenton and Princeton subsequently left no doubt as to who should be commander-in-chief.

Gates assumed command of the Northern Department on August 19 and led the army during the defeat of British General Burgoyne's invasion in the Battles of Saratoga.

While Gates and his supporters took credit for the victory, military action was directed by a cohort of field commanders led by Benedict Arnold, Enoch Poor, Benjamin Lincoln, and Daniel Morgan.

Arnold in particular took the field against Gates' orders and rallied the troops in a furious attack on the British lines, suffering serious injuries to his leg.

Gates stands front and center in John Trumbull's painting of the Surrender of General Burgoyne at Saratoga,[10][11] which hangs in the U.S. Capitol Rotunda.

By Congressional resolution, a gold medal was presented to Gates to commemorate his victories over the British in the Battles of Bennington, Fort Stanwix and Saratoga.

Gold and bronze replicas of that medal are still awarded by the Adjutant General's Corps Regimental Association in recognition of outstanding service.

[14] Gates (then unaware of Wilkinson's involvement) accused persons unknown of copying his mail and forwarded Conway's letter to the president of Congress, Henry Laurens.

[15][16] Gates then apologized to Washington for his role in the affair, resigned from the Board of War, and took an assignment as commander of the Eastern Department in November 1778.

In May 1780, news of the fall of Charleston, South Carolina, and the capture of General Benjamin Lincoln's southern army reached Congress.

Analysis of the debacle suggests that Gates greatly overestimated the capabilities of his inexperienced militia, an error magnified when he lined those forces against the British right, traditional position of the strongest troops.

Gates's principal accomplishment in the unsuccessful campaign was to cover 170 miles (270 km) in three days on horseback, heading north in retreat.

[25] The couple thereupon moved to an estate at Rose Hill in present-day midtown Manhattan, where the local authorities received him warmly.

[27] He died in his Rose Hill home on April 10, 1806, and was buried in the Trinity Church graveyard at the foot of Wall Street, though the exact location of his grave is unknown.