The first USS Ontario was a lake schooner

Schooner

A schooner is a type of sailing vessel characterized by the use of fore-and-aft sails on two or more masts with the forward mast being no taller than the rear masts....

 in the United States Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 during the War of 1812

War of 1812

The War of 1812 was a military conflict fought between the forces of the United States of America and those of the British Empire. The Americans declared war in 1812 for several reasons, including trade restrictions because of Britain's ongoing war with France, impressment of American merchant...

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Ontario was built as a merchant ship on Lake Ontario

Lake Ontario

Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north and southwest by the Canadian province of Ontario, and on the south by the American state of New York. Ontario, Canada's most populous province, was named for the lake. In the Wyandot language, ontarío means...

; purchased in October 1812; and placed in service in 1813, Sailing Master Joseph Stevens in command.

Part of Commodore Isaac Chauncey

Isaac Chauncey

Isaac Chauncey was an officer in the United States Navy.-Biography:Chauncey, born in Black Rock, Connecticut, 20 February 1779, was appointed a Lieutenant in the Navy from 17 September 1798...

's tiny Lake Ontario squadron protecting upstate New York

New York

New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

 from a seaborne British

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 and Canadian

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 invasion, Ontario supported an attack on York

Toronto

Toronto is the provincial capital of Ontario and the largest city in Canada. It is located in Southern Ontario on the northwestern shore of Lake Ontario. A relatively modern city, Toronto's history dates back to the late-18th century, when its land was first purchased by the British monarchy from...

, Canada, on 27 April 1813. General Zebulon Pike

Zebulon Pike

Zebulon Montgomery Pike Jr. was an American officer and explorer for whom Pikes Peak in Colorado is named. As a United States Army captain in 1806-1807, he led the Pike Expedition to explore and document the southern portion of the Louisiana Purchase and to find the headwaters of the Red River,...

 landed 1700 troops to raid the town while the U.S. squadron destroyed large quantities of stores and burned a schooner under construction. The warship then cooperated with troops attacking Fort George

Fort George, Ontario

Fort George National Historic Site is a historic military structure at Niagara-on-the-Lake, Ontario, that was the scene of several battles during the War of 1812...

 on 27 May, forcing a British evacuation of the Niagara Frontier. She then patrolled the Lake against British warship and merchantmen movements into the summer.

From 7–11 August, Ontario, still with Chauncey's 13-ship squadron, fought a running engagement with British Captain James Yeo

James Lucas Yeo

Sir James Lucas Yeo KCB was a British naval commander who served in the War of 1812.Yeo was born in Southampton on 7 October 1782, and joined the Royal Navy as a midshipman at the age of 10. He first saw action as a lieutenant aboard a brig in the Adriatic Sea, and distinguished himself during the...

's 6-ship group. Losing two ships on the 8th to heavy weather, the squadron had two more captured during the inconclusive exchange of fire on the 10th. A further sea fight on the 11th brought no more results but finally, a battle off York on 28 August succeeded in damaging two British ships and forced the enemy to flee into Burlington Bay

Burlington Bay

Burlington Bay, known more commonly as Hamilton Harbour, lies on the western tip of Lake Ontario, bounded on the northwest by the City of Burlington, on the south by the City of Hamilton, and on the east by Hamilton Beach and Burlington Beach...

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For the next year and one-half, Ontario remained on Lake Ontario on patrol against any British invasion attempts. Laid up in ordinary following the end of the War of 1812, the converted commercial schooner was sold on 15 May 1815 and returned to merchant service.