The home of the President of United States was officially named the White House in October 1901.
Construction of the building started in 1792, and the John Adams was the first President to occupy the building in 1800, even though it was far from finished. During the 19th century it was variously known as the Residence, Executive Mansion, Presidential Mansion, President's House and the White House.
The first mention of the name of White House is from a letter dated 24 April 1811 written b
y Francis J. Jackson, former Minister for the United States in Britain, in it he wrote “…the lightning that may issue from the clouds round the Capitol and the White House at Washington” As the name is in capitals, this would suggest that it was in current use.
Through the 19th century the White House became its popular name, but Congress and other government institutions still used the formal name of Executive Mansion in documents.
In October 1901 soon after Theodore Roosevelt became President, he altered all official stationery from Executive Mansion to White House. The name was selected because of its distinctiveness and its suitability for the residence of the chief executive of the United States, and to separate it from every other executive mansion in each of the States. The name was not changed after the end of his Administration.
 Documents Relating To New-England Federalism, 1800-1815 by Henry Adams
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