Herkimer's father had established himself as a successful trader and businessman amongst the Palatine Germans in the Mohawk Valley. Nicholas followed in his father's footsteps and eventually had a thriving farm and business. In addition to his trade operations, Herkimer also made money portaging boats and goods over the "Little Falls" area of the valley for a fee.

During the opening hostilities between England and the colonies, Herkimer was made Colonel of the Canajoharie Regiment of the Tryon County Militia. When Sir John Johnson fled to Canada in 1776, Herkimer was appointed to be Brigadier General of the four Regiments of Tryon County Militia. He would be using the experience he had gained as a militia lieutenant fighting with the British during the French and Indian War. This time however, he would be siding with the rebels and fighting against the British.

Learning that Fort Schuyler was besieged by St. Barry Leger's forces, Herkimer gathered together around 800 men of the Tryon County Militia and some Oneida Indians to march to the relief of the fortress. St. Leger learned of Herkimer's advance and sent a portion of his army, made up of loyalists and Indians, to halt him. Herkimer and his troops were ambushed near the Oneida village of Oriska (Oriskany) on August 6, 1777. Wounded in the leg early in the fighting, the brave Palatine continued to calmly direct his troops as he smoked his pipe. The battle raged on for hours as former friends, family, and neighbors fought savagely against one another. Finally, St. Leger's forces retreated back to the fort. The militia had failed to reach the fort, but they had stood fast and held their ground.

Once home, it was determined that Herkimer's leg need to be amputated. A novice surgeon performed the amputation and infection soon set in. Ten days later, while Herkimer was reading from his beloved family bible, the hero of the Mohawk Valley died.

Nicholas Herkimer