Early settlers to Royal Oak were farmers but the advent of the railroad soon brought about logging, milling and other industries. As early as 1891, when Royal Oak was a small village, there were only a few hundred residents. In the 10-year span from 1900 to 1910 the population grew to over 1,000. By the time Royal Oak was incorporated as a city
in 1921, the population had expanded to over 6,000.
Royal Oak received its name from Gov. Lewis Cass who encountered a stately oak tree, with a trunk considerably wider than most other oaks, while on an exploration of Michigan territory to disprove land surveyors' claims that the territory was swampy and uninhabitable.