For more than a dozen years, Marion Reid, 77, had walked past the statue of Theodore Roosevelt on his way to work in information technology at the American Museum of Natural History, an employer that he said often failed to treat African-Americans with dignity.

He drove into Manhattan around noon on Sunday to photograph the statue before officials carried out plans to remove it from its place of pride at the museum’s Central Park West entrance, only to find himself engulfed by about 150 protesters clamoring to preserve it. Among them were men in seersucker suits and women draped with pearls, people wearing MAGA hats and others waving Blue Lives Matter flags while chanting, “Save Teddy. Save our police. Save law and order.” About a dozen police were in the vicinity.

The protesters Sunday came to defy the nationwide movement that for decades has fought to bring down monuments that, like the Roosevelt statue, have been associated with racism, colonialism and oppression.

David Marcus, an organizer of the rally and a contributor to the conservative website The Federalist, addressed the crowd through a megaphone saying they were “brothers and sisters, and heirs to the most extraordinary experiment in freedom that the world has ever known. God bless Teddy Roosevelt.”

The museum announced last week that, with approval from the mayor and President Roosevelt’s family, it would remove the 80-year-old bronze statue.

The museum’s president, Ellen V. Futter, emphasized last week that the decision was not about Roosevelt but about the statue itself — namely its “hierarchical composition.” It features the president riding high on horseback, flanked by a Native American man and an African man, depicting them, Mayor Bill de Blasio said, “as subjugated and racially inferior.”