James McMillan was a U.S. Senator from the state

U.S. state

A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

 of Michigan

Michigan

Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....

.
McMillan was born in Hamilton, Ontario

Hamilton, Ontario

Hamilton is a port city in the Canadian province of Ontario. Conceived by George Hamilton when he purchased the Durand farm shortly after the War of 1812, Hamilton has become the centre of a densely populated and industrialized region at the west end of Lake Ontario known as the Golden Horseshoe...

 to William and Grace McMillan, both Scottish natives. He was educated in the public schools of Hamilton before moving to Detroit, Michigan

Detroit, Michigan

Detroit is the major city among the primary cultural, financial, and transportation centers in the Metro Detroit area, a region of 5.2 million people. As the seat of Wayne County, the city of Detroit is the largest city in the U.S. state of Michigan and serves as a major port on the Detroit River...

 in 1855 to embark on a career in business.

McMillan's first position was as a clerk for Buhl, Ducharme & Co., a wholesale hardware firm. At the age of 20, he left to become the purchasing agent for the Detroit & Milwaukee Railway.