1749 – The Abbé François Picquet builds a mission fort called Fort de la Présentation on the banks of the Oswegatchie River and the St. Lawrence River to convert the Iroquois Confederacy to Catholicism and to bring them to the side of France as his nation prepares for war with the British.

French leaders in New France support the construction of the fort as a crucial step to repair relations with the powerful Iroquois Confederacy, the most powerful Native American government in North America, which controls most of what is now upstate New York above the Mohawk Valley and western New York.

The Iroquois have a long history of friendly relations with the British who have designs on New France. The French control what is now Canada and the entire Mississippi Valley to New Orleans, pinning in the rapidly growing 13 British Colonies. Unfortunately, New France only has about 80,000 people thinly stretched across its widespread colony. The 13 British colonies have a population of more than a million people.

The Iroquois agree to allow Picquet to build his mission fort because they are growing concerned by the way the Britsh settlers keep encroaching on their territory in the Mohawk Valley. They are also uneasy over the British decision to build a fort at Oswego. 

 1755 – The Abbé Picquet’s mission Fort de la Présentation has attracted more than 3,000 Onondagas, Cayugas and other Iroquois to the side of France. In the 1750s, Montreal only had a population of 4,000. With such a sparse population, Picquet’s mission represents a large fighting force in the service of New France.

The French use the fort as a base of operations for attacks on the British in the Mohawk Valley, the Champlain Valley and the Ohio Valley. 

1755 – Warriors from la Présentation play a role in the defeat of Braddock and George Washington in the Ohio Valley.

1756 – Warriors join Gaspard-Joseph Chaussegros de Léry’s expedition which destroys Fort Bull (near present day Rome, NY).

1756 – Picquet and his warriors accompany Montcalm to help capture Oswego.

1756 – At the Albany Conference, Benjamin Franklin urges the British to destroy Fort de la Présentation.

1757 – Picquet and warriors accompany Montcalm at the battle of Fort William Henry and is blamed by many of the British for his failure to stop the massacre afterwards. This battle was depicted in James Fenimore Cooper's novel Last of the Mohicans. Picquet accompanies Montcalm to the battle at Fort Carillon, but his warriors do not join the battle.

1759 – The French begin evacuating Fort de la Présentation and construct Fort Lévis on Chimney Island to prevent a British attack up the St. Lawrence River on Montreal and Quebec.

1760 – For five days and nights, 300 French soldiers at Fort Lévis stand off 10,000 Anglo-American troops led by Sir Jeffrey Amherst, blocking them as they sweep down the St. Lawrence River on their way to Montreal. This is the last Battle of the French and Indian War.

1760 to 1796 - The British occupy the fort and rename it Fort Oswegatchie. The British use Oswegatchie during the Revolutionary War from 1775 to 1783. Captain George Forster led a detachment of the King’s 8th from Fort Oswegatchie and defeated the Americans at the Battle of the Cedars in 1776.

June 10, 1779 – Fort Oswegatchie was attacked by an American detachment from Fort Stanwix and one man was taken prisoner. A retaliatory attack on Fort Stanwix took 29 prisoners and three scalps.

September 1780 – A detachment from Fort Oswegatchie burned houses, harvest-filled barns and killed a number of cattle in the area of Fort Dayton.

June 1781 – An expedition to Canada Creek area took seven prisoners, killed two “rebels,” burned houses, barns and destroyed 100 milk cows and a number of horses.

June 1782 – Capt. Robertson, Fort Commandant since May 1779, led a destructive attack on Ellice’s mill at Little Falls. Wheat, flour and a quantity of Indian corn belonging to Congress and approximately the same amount owned by local inhabitants plus a quantity of salt pork and beef were destroyed. This raid is mentioned in the novel Drums Along The Mohawk.

After the cessation of hostilities, the British refused to give up Fort Oswegatchie to the victorious Americans. It was one of the five forts along the frontier they retained. Jay’s Treaty signed November 19, 1794 contained the provision that the British evacuate the frontier posts by June 1, 1796.
 

1796 – The first settlers under the American flag arrived August 11, 1796, led by Nathan Ford, land agent for the proprietor, Samuel Ogden for whom Ogdensburg was named.

1812 – An American rifle company is ordered to Ogdensburg at the outset of the War of 1812. They occupy the remains of the fort they call Fort Presentation. In August they raid Gananoque across the St. Lawrence River.

September 1812 – A British force launches a naval attack on the Ogdensburg. The attack is repelled by General Jacob Brown and Captain Benjamin Forsyth.

1813 – Capt. Benjamin Forsyth leads 300 men from Ogdensburg to Brockville, Upper Canada (Ontario), on February 7 to release American prisoners and take military stores. On February 22, the British troops under Lt. Col. ‘Red George’ MacDonnell march cross the ice-covered St. Lawrence River from Prescott to capture Ogdensburg.