in
New York City served as the executive mansion for
George Washington, the first
President of the United States, from February to August 1790. In
Detroit during the
American Revolution, Macomb and his brother
William continued their fur trade with
British and Native Americans. They conducted a huge volume of business with the British government post at Detroit, supplying the militia as well as the colonial Indian Department. The brothers took a partner because of the volume of their business, and in fall 1781, invested 100,000 dollars in New York currency in the business. The city was rapidly rebuilding after the war, and men of Loyalist leanings, such as Macomb, were generally not discriminated against. They just wanted to get on with business. Macomb became a successful land
speculator and shipping magnate in New York. He purchased large tracts of
land in
Georgia,
Kentucky, and
North Carolina for resale. In 1788, he built a four-story brick city mansion on
Broadway one block south of
Trinity Church; the house had a frontage along one side. In part Macomb needed the space for his large household; by 1790, he was a widower with 10 children at home. His household included 25 servants, among them 12
enslaved African Americans. Macomb was the third-largest slaveholder in the city, as by that time slaveholding residents generally owned only a few slaves as domestic servants or skilled labor. New York did not pass legislation for gradual abolition of slavery until the early 19th century. In 1790, the government of New York City leased Macomb's New York City house to serve as the
second presidential mansion of the temporary capital, after the first, the
Samuel Osgood House on Cherry Street, proved too small. George Washington occupied the Macomb mansion from February to August 1790. The mansion was later adapted as a landmark hotel. During this period, Macomb became active in civic affairs, using his expertise to purchase materials and direct the conversion of City Hall into Federal House for the temporary capital. He assisted the state legislature in supervising the construction of a building to house the state archives, and served two terms in the state assembly. Macomb also served as the first treasurer of "New York's first scientific body, the Society for the Promotion of Agriculture, Arts and Manufactures." In July 1791, Alexander Macomb married again, to the young widow Mrs. John Peter Rucker, née Jane Marshall. They had another seven children together. That year he purchased his largest tract of land of all, from the State of New York: 3,670,715 acres (14,855 km2), which has since known as "
Macomb's Purchase." The tract included much of northern New York, along the
St. Lawrence River and eastern
Lake Ontario, including the
Thousand Islands, and he paid about twelve cents an acre. The state took control of this land after the British ceded their own and Iroquois lands to the United States under terms of the treaty at the end of the war. Four of the six Iroquois tribes had been allied with the British but none was consulted during the treaty negotiations. The state's treaty and sale of this land was never ratified by the
United States Senate. In the late 20th century, some of the tribes filed land claims for compensation, claiming that New York state did not have the authority to treat with them, since the land cessions were never ratified by the U.S. Senate; some of the land claims were upheld by the
U.S. Supreme Court.) The purchase was divided into ten large townships. From this purchase are derived the deeds for all the lands that are now included in
Lewis,
Jefferson,
St. Lawrence, and
Franklin counties, and portions of
Herkimer and
Oswego counties. Contrary to his expectations, Macomb's enterprise was a failure. Sales of land did not keep pace with the due dates for payments. During the
Panic of 1792, which further depressed land sales, Macomb was taken to debtors' prison with over $300,000 in debt. He never regained his fortune. As economic conditions improved, some land speculators later made huge amounts of money from their turnover of New York lands. ==Personal life==