Its daily responsibilities were largely civil in nature, such as the administration of justice, the management of the fur trade, and the employment of blacksmiths, teachers, and missionaries.

During the period 1755–1830, the mission of the Indian Department can be summarized as protecting the indigenous peoples from exploitation by traders and land speculators (one of the goals of the Royal Proclamation of 1763; negotiations with the First Nations about boundaries between their land and that of the agricultural colonists (such as the Treaty of Fort Stanwix 1768); distribute the gifts that the government gave to the indigenous people in order to create goodwill.

The superintendent of the northern department, responsible for negotiations with the Indians living north of the Ohio River, was Sir William Johnson who held the position until his death in 1774.

[7] His sister Molly Brant also played a critical role in the Indian Department during this time, and was afterwards granted a pension from the British government for her services during the Revolution.

In revenge, Sir John Johnson and his Indigenous allies carried out a substantial raid against the settlements of upstate New York in 1780, known as the Burning of the Valleys.

[9] The Indian Department also saw extensive fighting in the Ohio Valley region, where Alexander McKee, Matthew Elliott, and Simon Girty were among the most effective Loyalist partisans of the war.

[10] Major engagements involving the Indian Department on this front included Captain Bird's Invasion of Kentucky, Crawford's Defeat, and the Battle of Blue Licks.

The British Indian Department was particularly successful mobilizing warriors against the Americans in the Ohio Country following the massacre at Gnadenhutten of 96 pacifist Christian Munsee by Pennsylvania militiamen on March 8, 1782.

[12] During much of the period after the Revolution, the Indian Department was deeply concerned with the ongoing struggle between the Indigenous communities of the Ohio Valley and the young American republic.

This clause allowed the Indian Department to continue to maintain close connections with Indigenous communities living in U.S. territory, such as the Shawnee, the Odawa, the Potawatomi, and the Dakota.

[14] Following the outbreak of the Revolutionary War, and again after the signing of Jay's Treaty, many members of the Indian Department removed themselves from their homes in what is today the United States and established themselves in Canada as Loyalists.

Sir John Johnson became one of the leading men of the Montreal region, while Alexander McKee was one of the founding settlers in western Upper Canada.

The migration of the Six Nations of the Grand River with Joseph Brant and the Mohawks of the Bay of Quinte with John Deseronto to the Province of Quebec was part of this movement.

[17][18] During the War of 1812, a uniform was established for the Indian Department for the first time, consisting of a red jacket faced with green on the collar and cuffs.

However, even after this setback the Indian Department won a number of important victories alongside its Indigenous allies, including the Battle of Michilimackinac and the Siege of Prairie du Chien in the summer of 1814.

Lieutenant Colonel Robert McDouall, temporarily in charge of the Indian Department at Michilimackinac, wrote many lengthy dispatches decrying the abandonment of Great Britain's Indigenous allies.

During the fifteen years leading up to the transfer of the Indian Department, many of its old practises were discarded, including most prominently the annual giving of presents to those Indigenous communities who were in alliance with the British Crown.