On July 8, 1771, Tryon arrived in the
Province of New York and became its governor. In 1771 and 1772 he was successful in having the assembly appropriate funds for the quartering of British troops and also on March 18, 1772 the establishment of a militia. Funds were also appropriated for the rebuilding of New York City's defenses.
In 1772, opposition in New York was strong against the
Tea Act. In December, the
Sons of Liberty "persuaded" the tea agents to resign. Tryon proposed to land the tea and store it at Fort George. The Sons of Liberty were opposed and
Alexander McDougall said, "prevent the landing, and kill [the]governor and all the council". When news of the
Boston Tea Party arrived on December 22, Tryon gave up trying to land the tea. He told London the tea could only be brought ashore "only under the protection of the point of the bayonet, and muzzle of cannon, and even then I do not see how consumption could be effected". In 1774, the New Yorkers dumped their own consignment of tea into the harbour.
On December 29, 1773 the governor's mansion and all its contents were destroyed by fire. The New York assembly appropriated five thousand pounds for his losses.
On April 7, 1774 Tryon departed for a trip to England.
Cadwallader Colden was the acting governor of New York in Tryon's absence. He arrived back in New York on June 25, 1775 after the
American Revolutionary War had begun.
Isaac Sears in July returned from the Continental Congress with orders to put Tryon under arrest, but George Washington had ordered Philip Schuyler the commander in New York to leave Tryon alone. On October 19, 1775, Tryon was compelled to seek refuge on the British sloop-of-war
Halifax in New York Harbor. In 1776, he dissolved the assembly and called for new elections in February. The new assembly was for independence and Tryon dissolved it.
During the spring and summer of 1776, Tryon and New York City's mayor,
David Matthews, were conspirators in a miserably bungled plot to kidnap General George Washington and to assassinate his chief officers. One of Washington's bodyguards,
Thomas Hickey, was involved in the plot. Hickey, while in prison for passing counterfeit money, bragged to his cellmate Isaac Ketcham about the kidnapping plot. Ketcham revealed it to authorities in an effort to gain his own freedom. Hickey was court-martialed, and was hanged for mutiny on June 28, 1776.
In June, Admiral Howe arrived in New York City with the British army. Howe placed New York under martial law with
James Robertson as the military commander. Tryon retained his position as governor, but with little power.
In early 1777, Tryon was given the rank of major-general of the provincials. In April, he was ordered to invade Connecticut and march on the city of Danbury to destroy an arsenal there. In May, 1778 he was given the rank of major-general in the British army, but in America only, and also the colonelcy of the
70th Regiment of Foot. He became the British commander of the British forces on Long Island.
Tryon had long advocated engaging in attacks on civilian targets, but Clinton turned down Tryon's proposals. In July 1779, Tryon commanded a series of raids on the Connecticut coast, attacking New Haven, Fairfield, and Norwalk, burning and plundering most of Fairfield and Norwalk. Tryon's raids were intended to draw American forces away from the defense of the Hudson valley. In spite of pressure from Governor Trumbull, George Washington did not move his troops. Americans condemned him for making war on "women and children", and the British commander Clinton was also indignant for Tryon disobeying his orders. Tryon found approval in his conduct from
Lord Germain, but Clinton refused to give Tryon any further significant commands.
In September 1780, Tryon returned to his home in London, England. He directed the affairs of his
70th Regiment of Foot still in the colonies and he gave directions in 1783 for the regiment to be brought back to England for disbandment. In 1782 was promoted to lieutenant-general. In 1784 he was made colonel of the
29th Regiment of Foot which was stationed in Canada.
He died at his home in London on January 27, 1788 and was buried at St. Mary's Church, Twickenham, Middlesex.