Part of a British unit that seized Fort Vincennes, Indiana, in 1778, Givins was captured by American forces when they retook the post in 1779 and spent two years as a prisoner of war.

[4] In 1802 Givins built a large estate west of Toronto on land he received as a loyalist fighter in the American Revolution.

[2] In his role as an officer in the Indian Department, Givins helped coordinate a band of Mississauga warriors during the Battle of York on April 27, 1813.

His performance there was favourably noted by Sir Roger Hale Sheaffe, when the men under his command were the first to engage the landing American troops.

After coming under fire from the Americans, and their own relief failing to arrive, he and his men retreated to Pine Grove where his wife Angelica attended to their wounds.

The success of the Credit Mission was noted in Henry Charles Darling's report on the state of the province's Indians, and the settlement became a model for the reserve system.