"Old Hickory" was the nickname of Andrew Jackson, the seventh president of the United States. He earned his nickname defending New Orleans in the War of 1812, when his men declared he was "as tough as old hickory." The nickname followed him for the rest of his life.
Jackson's nickname became so iconic that some of the streets and geographic areas named after him use it instead of his given name. Old Hickory Boulevard in Nashville is named in his honor, as is the Old Hickory suburb and Old Hickory Lake.
Jackson's most-famous exploits in the War of 1812 actually took place after its conclusion. The Treaty of Ghent was signed in December of 1814, but word had not reached New Orleans when the British attacked it and were repelled the following month.