Portland will make history today, when Michael Brennan is sworn in as the first popularly elected mayor to take office since 1923.

Brennan is scheduled to address the city for the first time this evening, and his remarks will likely be focused on the future and his plan to lead the city during a period of transition. But the road that led to that event is one worth remembering.

Starting in 1832, Portland elected mayors who wielded unchecked power to run the city. Most notable was James Phinney Baxter, first elected in 1893, who singlehandedly saved the Eastern Promenade from development, established the city park system and persuaded Back Cove property owners to relinquish land that could become a landscaped boulevard, one of the city’s trademarks to this day.

The early 20th century marked the political ascendancy of immigrant groups — Irish, Italian and Jewish — and a backlash from the Protestant establishment.

With the support of the Ku Klux Klan, a committee of Yankee civic leaders led an effort to replace the elected mayor with a five-member City Council, moving power from the immigrant wards to the Protestant neighborhoods.

Over time, the ugly ethnic politics of the ’20s gave way to a period of professional management, where elected officials played a secondary role to experts they hired.

City managers like John Menario, Robert Ganley and Joe Gray oversaw government during periods of growth and private sector investment, leaving Portland a successful city, that receives high marks for livability.

Brennan’s election follows a process that began in 2008, leading to the election of a charter commission, which last year recommended recreating an elected mayor who would work with a city manager and sent the question to the voters.

After a five-month campaign with 15 contenders, Brennan wound up on top, getting 56 percent of the vote following 13 rounds of instant runoffs.

What happens after he takes the oath will be Portland’s next chapter. As the first elected mayor in 88 years, Brennan’s vision and response to the challenges he will face, starting with his first council meeting Wednesday night, will go a long way to define the job and a new direction for the city.