John and Walter came to America in the 1750s from Ramelton or Rathmullan, County Donegal, and served in the British Army during the French and Indian War.

His maternal aunt, Mary Livingston, was the wife of James Duane, a respected lawyer, patriot, New York politician, and judge.

As acting midshipman, he joined the sloop of war Delaware, June 11, 1799, to cruise against French privateers and warships in the West Indies to August 1800.

Appointed a midshipman on August 20, 1800 (warrant subsequently altered to take rank from date of his original entry, June 11, 1799).

On close of the Quasi-War with France, he resumed nautical studies, then had blockade duty off Tripoli in Constellation and Philadelphia.

[3] On September 16, 1814, Patterson raided the base of the pirate Jean Laffite at Barataria Bay, in cooperation with Colonel George T. Ross, capturing six schooners and other small craft.

[3] In that same month, he refused Andrew Jackson's request to send his few naval units to Mobile Bay where Patterson knew they would be bottled up by a superior Royal Navy fleet.

His little fleet[weasel words] delayed the enemy until reinforcements arrived,[citation needed] then gave artillery support in defense of the fortifications on the right bank of the Mississippi.