The state of Maine and the Ku Klux Klan. Improbable as it sounds, the KKK took root in Maine in the 1920s, reaching such heights that it helped elect Governor Ralph Owen Brewster, the mayors of Rockland, Bath, Saco and Westbrook and many others.

This shocking time in Maine’s history, omitted from history textbooks for nearly 100 years, will be explored and explained by author Mark Alan Leslie at Boothbay Harbor Memorial Library at 6 p.m. Wednesday, Sept. 19.

“While African-Americans were few in Maine at that time, the KKK’s targets were French-Canadians, Catholics and Irish and Polish immigrants as well as Jews,” says Leslie. “And were they effective! The Klan’s Maine membership reached a reported 150,000, nearly 20 percent of the state’s population of 790,000, in 1923-25. When the KKK held its first state conclave in a forest outside Waterville in 1923, nearly 15,000 attended.”

The Midcoast area was not immune to the Klan’s recruitment.

Hodgdon Buzzell, president of the Maine State Senate, was a proud member of the Belfast KKK klavern and Rockland’s citizens elected Carlton Snow, who was endorsed by the Klan. Meanwhile, Rev. E.V. Allen of Rockland was one of the first to join the Rockland Klan and in respect for his diligent service the Klan officials elevated him to the office of Grand Klaliff, State of Maine.

Meanwhile, parades were held in Portland, Gardiner, Milo, Dexter, Brewer and elsewhere.

Leslie will tell the tale of the rise and fall of this organization which, now and again, still makes headlines in Maine today.

The Monmouth resident’s fictional novel, “The Crossing,” is a sweeping — and ultimately uplifting — look at the KKK’s impact on a small western Maine town in 1923.

Called “a seasoned wordsmith…in the class of John Grisham” by the American Family Association’s AFA Journal, Leslie burst onto the scene in 2008 with “Midnight Rider for the Morning Star,” then earned Featured Book status from Publishers Weekly for his 2015 novel, “True North: Tice’s Story,” about the Underground Railroad in Maine.

After his talk, Leslie will be available to sign his novels, including three contemporary action/adventures, the latest being “The Last Aliyah,” published this spring.