As the American Revolution grew closer, Peter joined the Albany militia.
While he lacked the experience many older officers, he was a tactful and persuasive leader.
Even at his young age, he was over six feet tall, and had a commanding presence.
This, along with his family connections, earned him a Lieutenant's rank.
Invasion of Canada (1775-1776)
He joined the Continental Army and was made a Major on June 30, 1775 and served as a field commander in the 2nd New York regiment.
Gooje Van Schaick was nominally Colonel, he had raised the regiment and served as its commander from Albany.
Lt. Colonel Peter Yates was the primary field commander, but remained as post commander of Fort George when Major Gansevoort led much of the regiment north with Montgomery's forces for the Invasion of Canada.
Peter led his men during the siege of the Fort at St. Johns, today known by its French name of Saint-Jean-sur-Richelieu, Quebec. In late October, to improve the effect of the siege, Montgomery sent Gansevoort down the river to seize Fort Chambly. At Chambly, they captured over 120 barrels of needed gunpowder and a huge mortar which they nicknamed the Old Sow. They also took about 100 prisoners of the Welch Fusilier garrison and their young Captain, John Andrè. Montgomery used it to the Old Sow to open fire on St. Johns, which was compelled to surrender on November 2, 1775. He took part in the capture of Montreal, although he became ill during that attack. He started on the advance to Quebec, but by the time the force reached Three Rivers he was being carried on a stretcher.
Gansevoort returned to Montreal, and spent the winter as one of the sick with the occupation force.
By the spring of 1776 the invasion fell apart at Quebec; Montgomery had been killed, and Benedict Arnold was wounded.
Major Gansevoort had recovered to the point where he led the remaining New York forces south in a fighting withdrawal that stopped the British advance at Lake Champlain.
As recognition, in June of 1776 he was put in command at Fort George.
In November he was made a full Colonel and given command of the 3rd New York Regiment. which he recruited and trained in early 1777.
Lt. Colonel Marinus Willett became his 2nd in command.
His area of responsibility was extended from the Hudson River valley and Fort Edward and Fort George, along the Mohawk River Valley to Fort Oswego in the northwest.
This was to be the axis of Colonel Barry St. Ledger's attack during the Saratoga Campaign.
The 3rd New York did not have the men and equipment to extend that far, even with the support of local militia units.
He conceded Fort Oswego to the British, and elected to defend Fort Stanwix (near modern Rome, New York).
The fort had been abandoned after the French and Indian War.
Gansevoort and Willett restored the fort and strengthened its defenses.
The hurriedly set up a garrison, getting the last boatload of supplies into the Fort under fire from St. Ledger's advance force.
Gansevoort with about 750 men held the fort which was now strong enough to resist a simple assault.
St. Ledger arrived on August 2 with about 860 mixed troops and 1000 Indians and the siege began.
The American force refused to be intimidated, and Peter led a spirited defense.
He held for three weeks, in spite of the failure of General Nicholas Herkimer's relief at the Battle of Oriskany.
While St. Ledger was occupied during that battle, he ordered Willett to make a sortie which destroyed much of the British supplies.
Abandoned by his Indians, the siege was broken on August 22, and Benedict Arnold arrived as relief on the 24th.
He received the grateful thanks of the Congress, as John Adams noted that "Gansevoort has proven that is possible to hold a fort."
In the reorganization and downsizing of the New York Line in 1781, Gansevoort was left with no assignment. in the Continental Army.
He returned home and became Brigadier General of the Albany County Militia.
Peter had married Catherine (Katy) Van Schaik on January 12, 1778 in her family's home at Albany.
She was the daughter of Wessel and Maria Van Schaik, and her brother Goose had been Peter's commander and Colonel in 1775.
Over the years, they had at least three children; Peter Jr., Leonard, and Maria.
Leonard's son Guert Gansevoort had a distinguished naval career that spanned 45 years.
Maria married Alan Melville in 1814, and their son was the author Herman Melville.
In 1809, he was made a Brigadier General in the United States Army and commanded the Northern Department.
In 1811 he was called on to preside over the court-martial of General James Wilkinson who was charged as an accomplice in Aaron Burr's western conspiracy.
Wilkinson was found not guilty, and the court adjourned on Christmas Day.
Hurrying back to his family, Peter's old illness returned, and he never recovered.
He died at home in Albany on July 2, 1812.
Siege of Fort Stanwix
Main article: Fort Stanwix.1778-1781
Gansevoort eventually turn Fort Stanwix over to a garrison of the 1st New York.
He moved his headquarters to hi new command at Fort Saratoga (near modern Schuylerville, New York.
He led the his regiment in the Sullivan Expedition of 1779.
He had another bout of illness that winter (1779-1780) and returned home for a while, but by July of 1780 he was back with the 3rd at West Point.
He was assigned to command the New York Brigade, and reestablished his headquarters at Fort Sarratoga.After the revolution
Peter continued to make his home in Albany where he operated the family brewery.
He expanded his farms, adding grist mills and a lumber mill, in the area that eventually became Gansevoort, New York.
He served for a while as sheriff of Albany County, as a commissioner of Indian affairs, and continued his support of the military in the militia and as a quartermaster.Further Reading