He was born in Geneva, Switzerland of a wealthy family, emigrating to Massachusetts in 1780. For a brief period he attempted to set himself up in business, and for an even briefer time taught French at Harvard, finally purchasing land in Pennsylvania and moving there in 1784. (His land was in Virginia when he bought it but became part of Pennsylvania soon afterward.)
Almost immediately he became active in Pennsylvania politics; he was a member of the state constitutional convention in 1789, and was elected to the state legislature in 1790. He won election to the United States Senate in 1793 but was disqualified, because of his length of citizenship, after he had already taken the Oath of Office. Entering the House of Representatives in 1795, serving in the fourth through sixth Congresses, he went on to become majority leader and put a great deal of pressure on Treasury Secretary Oliver Wolcott Jr to maintain fiscal responsibility. He also helped found the House Committee on Finance (which would evolve into the Ways and Means Committee) and often engineered withholding of finances by the House as a method of overriding executive actions to which he objected.
Among these was the Quasi-War, of which he was an highly vocal foe. His measures to withhold naval appropriations during this period were met with extreme animosity by the Federalists, who accused him of being a French spy. It was the opinion of Thomas Jefferson that the Alien and Sedition Acts were passed largely as a way to rein in Gallatin.
When Jefferson became President, he appointed Gallatin Secretary of the Treasury. Gallatin served in that post for thirteen years, the longest term in history for that office. During the first part of his tenure he made great progress in balancing the federal budget. The United States was able to make the Louisiana Purchase without a tax increase in large part due to Gallatin's efforts. Gallatin also involved himself in the planning of the Lewis and Clark Expedition, mapping out the area to be explored.
Later the increase in expenditures for the War of 1812 caused much of the progress Gallatin had made in balancing the budget to be set back. James Madison sent him in 1813 as the U.S. representative to a Russian-brokered peace talk, which Britain ultimately refused, preferring direct negotiations. Gallatin resigned as Secretary of the Treasury to head the U.S. delegation for these negotiations in France and was instrumental in the securing of the Treaty of Ghent, which brought the war to a close.
At the war's close Gallatin, preferring to remain in France, was appointed U.S. Minister to that country and remained in this post for another seven years. He returned to America in 1823 and was selected by the Democratic-Republican Party as its vice-presidential candidate, but was dissuaded by Martin Van Buren from accepting. He returned home to Pennsylvania where he stayed until 1826.
That year, John Quincy Adams appointed him minister to Great Britain, in which position he served to 1827, later returning and settling in New York City. Here Gallatin indulged an interest in the ethnology of Native Americans, publishing a treatise on the subject in 1836 and founding the American Ethnological Society in 1842. He also became president of the National Bank (which was later renamed Gallatin Bank). Gallatin died in Astoria on Long Island and is interred at Trinity Churchyard in New York City.
The Writings of Albert Gallatin (3 volumes, 1879) was edited by Henry Adams, who also became his biographer with Life of Albert Gallatin (1879). Gallatin's portrait was on the front of the $500 bill issued in 1862-3, and on the standard 1¼¢ stamp from 1967-73.