Theodore Roosevelt, known for his boundless energy and brash, adventurous spirit, possessed one of the biggest personalities of any American president. But, he once said, “It is a quality of strong natures that their failings, like their virtues, should stand out in bold relief.”

That could certainly be said of the 26th president, whose complex legacy includes not just his achievements as a progressive reformer and conservationist who regulated big business and established the national park system. He also believed firmly in the existence of a racial hierarchy, which shaped his attitudes on race relations, land rights, American imperialism and the emerging—and disturbing—science of eugenics.

“The force of race in history occupied a singularly important place in Roosevelt’s broad intellectual outlook,” wrote Thomas G. Dyer in Theodore Roosevelt and the Idea of Race. Roosevelt believed fundamentally that American greatness came from its rule by racially superior white men of European descent.

Roosevelt maintained that although white men held firm at the top of the social hierarchy, “inferior” races could rise from their lower stations. “Roosevelt believed that individuals could learn positive traits within their lifetime and assumed racial mobility was within human control,” says Michael Patrick Cullinane, a history professor at London’s University of Roehampton and author of Theodore Roosevelt's Ghost: The History and Memory of an American Icon. But Roosevelt didn’t come to those ideas himself. According to Cullinane, his racial ideology drew on his readings of leading evolutionary theorists such as Jean-Baptiste Lamarck and Charles Darwin.

Roosevelt “admired individual achievement above all things,” wrote biographer Edmund Morris—which is why he became the first president to invite an African American to dine at the White House when he broke bread with Tuskegee Institution founder Booker T. Washington just weeks after his inauguration. “The only wise and honorable and Christian thing to do is to treat each Black man and each white man strictly on his merits as a man, giving him no more and no less than he shows himself worthy to have,” Roosevelt wrote of his meeting.

Roosevelt also defended Minnie Cox, the country’s first African American female postmaster, after she was driven out of Indianola, Mississippi, because of the color of her skin. He appointed Black Americans to prominent positions, such as his nomination of Dr. William Crum as customs collector in Charleston, South Carolina, which drew considerable political opposition and this presidential response: “I cannot consent to take the position that the door of hope—the door of opportunity—is to be shut upon any man, no matter how worthy, purely upon the grounds of race or color.”

In spite of those words, though, Roosevelt hardly saw all Black Americans as equals. “As a race and in the mass they are altogether inferior to the whites,” he confided to a friend in a 1906 letter. Ten years later, he told Senator Henry Cabot Lodge that “the great majority of Negroes in the South are wholly unfit for the suffrage” and that giving them voting rights could “reduce parts of the South to the level of Haiti.”

Roosevelt also believed that Black men made poor soldiers. He denigrated the efforts of the buffalo soldiers who fought alongside his men at San Juan Hill during the Spanish-American War, falsely claiming that they ran away under fire. “Negro troops were shirkers in their duties and would only go as far as they were led by white officers,” he wrote. In reality, the buffalo soldiers served with distinction, and several men were officially recognized for their bravery. Twenty-six died on the slopes of San Juan Hill.

As for Native Americans, Roosevelt’s considerable time spent ranching in the Dakota Territory only hardened his mindset toward them, years before he became president. “I don’t go so far as to think that the only good Indian is the dead Indian,” he said in 1886, “but I believe nine out of every ten are, and I shouldn’t like to inquire too closely into the case of the tenth. The most vicious cowboy has more moral principle than the average Indian.”

Roosevelt viewed Native Americans as impediments to the white settlement of the United States and believed that white frontiersmen had forged a new race—the American race—by “ceaseless strife waged against wild man and wild nature.”

As president, he favored the removal of many Native Americans from their ancestral territories, including approximately 86 million acres of tribal land transferred to the national forest system. Roosevelt’s signature achievements of environmental conservation and the establishment of national parks came at the expense of the people who had stewarded the land for centuries. Roosevelt also supported policies of assimilation for indigenous Americans to become integrated into the broader American society. These policies, over time, contributed to the decimation of Native culture and communities.

Roosevelt’s attitudes toward race also had a direct impact on his foreign policy as president, says Cullinane: “Because he believed that white Anglo-Saxons had reached the pinnacle of social achievement, he thought they were in a position to teach the other peoples of the world who had failed to reach such heights. The United States would help tutor and uplift the Western Hemisphere.”

That worldview formed the foundation of Roosevelt’s vocal support of American imperialism, and in the White House he presided over an expanding overseas empire that included territories won in the Spanish-American War including Puerto Rico, Guam, Cuba and the Philippines. His Roosevelt Corollary to the Monroe Doctrine, also known famously as his “big stick” foreign policy, laid the foundation for a more interventionist policy in Latin America. He also extended American influence in the region by fomenting a rebellion in Panama that resulted in American construction of the Panama Canal.

And his desire to reset racial hierarchies wasn't limited to the Western Hemisphere. “It is of incalculable importance that America, Australia, and Siberia should pass out of the hands of their red, black and yellow aboriginal owners," Roosevelt wrote in his 1889 book _The Winning of the West, "_and become the heritage of the dominant world races.”

Roosevelt’s racial philosophy of white superiority dovetailed with his support of the eugenics movement, which advocated selective breeding to engineer a race of people with more “desirable” characteristics, and sterilization of “less desirable” people, such as criminals, people with developmental disabilities—and for some, people of color. “Society has no business to permit degenerates to reproduce,” he wrote in 1913. “Some day we will realize that the prime duty, the inescapable duty of the good citizen of the right type is to leave his or her blood behind him in the world; and that we have no business to permit the perpetuation of citizens of the wrong type.”

“Men must be judged with reference to the age in which they dwell,” Roosevelt said in a 1907 speech at the dedication of a monument to the Pilgrims. In his era, Roosevelt was hardly alone in his advocacy for racial hierarchies, American imperialism and eugenics, which became the basis of compulsory sterilization laws enacted by more than 30 states. The man who defeated him in the 1912 presidential campaign, Woodrow Wilson, shared similar views on race, and prominent figures such as Alexander Graham Bell, John D. Rockefeller and Winston Churchill supported the eugenics movement.

In the context of his time, “Roosevelt engaged meaningfully with the idea of race. He read and published on leading evolutionary thought," Cullinane says. "That said, there were also more progressive voices in Roosevelt’s day that he dismissed.”