BRIEF HISTORY DURING THE SNOW ERA (1813-58)
Buckingham Palace originated as Buckingham
House, which was built in 1702-5 for John Sheffield, 1st Duke of Buckingham
at the site of the later Palace.
King
George III (1738-1820, see picture) purchased Buckingham House in 1762 from the Duke's son, Sir Charles
Sheffield, following the King's marriage to Charlotte of Mecklenburg-Strelitz.
The
building was remodeled and remained one of the King's homes until 1820 when he
died and was followed to the throne by King George IV (1762-1830 -- see
picture).
By 1826, King George decided to convert the
Buckingham House into a palace and chose John Nash as architect. Nash
reduced Buckingham House to its shell, and replaced it with Buckingham Palace,
including a large Marble Arch
commemorating military victories which
was later moved to the north-east corner of Hyde Park in 1851. Unfortunately, the reconstruction of the Palace was
still not completed at the time of King George's death in 1830.
Thus he never lived
there, nor did his successor, King William IV (1765-1837 -- see
picture) who died in 1837, although by then
the building had been completed. 
When Queen Victoria (1819-1901 -- see picture) arose to the throne in 1837, she moved out of Kensington Palace and made Buckingham Palace her home. A new front wing was built on the east side of the palace in 1841-47, replacing the Marble Arch, providing more room for the Queen and her expanding family.
The 1859 map shows the Palace in two cells, O 12 and O 13.
Sources:
Weinreb B, Hibbert C (eds). The London Encyclopaedia, 1993.
Anonymous. Buckingham Palace, Official Guide, 1994.