For decades after his death in 1885, Ulysses S. Grant suffered a reputation as one of the nation’s worst presidents, consistently ranking in the bottom 10 in polls of historians. But in more recent years, historians have taken another look at the Civil War hero. Popular biographies, such as Ronald C. White’s American Ulysses (2016) and Ron Chernow’s Grant (2017), have made compelling cases that Grant's presidency merits reexamination, and that his contributions while in office were more substantial than he's been given credit for in previous decades. At a time when the nation was still recovering from the trauma of civil war, he worked to knit together the frayed Union, lift up formerly enslaved people and advocate a humane, if not enlightened, policy regarding Native Americans.

No one might be more surprised by this reputational revival than Grant himself. His autobiography, published in two volumes in 1885, covers some 1,200 pages, beginning with a discussion of his ancestors and ending with his Civil War years. His presidency is hardly mentioned.

Grant’s farewell message to Congress in 1876 shows he sensed that history might judge him harshly. “Mistakes have been made, as all can see and I admit,” he wrote. “But I leave comparisons to history, claiming only that I have acted in every instance from a conscientious desire to do what was right, constitutional, within the law, and for the very best interests of the whole people. Failures have been errors of judgment, not of intent.”

Two years later, the New York Sun put it another way, calling Grant “the most corrupt President who ever sat in the chair of Washington.”

So how good (or bad) president was he? Here is some of the historical evidence.

READ MORE: 10 Things You May Not Know About Ulysses S. Grant

There’s no denying that Grant left office under a very large cloud. From beginning to end, his Administration produced a swirl of scandals. While none rose to the notoriety of a Watergate or Teapot Dome, their sheer numbers must have been dizzying to Americans at the time.

Grant’s attorney general, secretary of war, secretary of the navy and secretary of the interior were all accused of taking bribes. His private secretary was implicated in a conspiracy to cheat the government out of tax revenue from the production of whiskey. The robber barons Jim Fisk and Jay Gould tricked Grant into aiding their scheme to manipulate the gold market, leading to a national financial panic known as Black Friday. Grant’s own brother Orvil, one of many relatives he put on the government payroll, was exposed in a kickback scheme that made the military overpay for provisions.

And that’s just a sampling.

READ MORE: The Whiskey Ring and America's First Special Prosecutor

Grant’s defenders, then and now, noted that he hadn’t personally benefitted from any of these crimes and maintained that he was an honest man surrounded by scoundrels—a line of argument that would be revived on behalf of Richard Nixon during the Watergate scandal a century later.

The ex-general had taken office with little political experience, Hamlin Garland noted in an 1898 biography, and found himself “pitted against the keen, shrewd, practiced manipulators of public affairs.”

“It was a time of speculation, of cupidity, and of corruption,” Garland added. “The war being over, the people had turned their attention to making money, and the corruption that was in private life had...rotted official life. The administration shared the characteristics of the times.”

Chernow, writing from a 21st-century perspective, makes much the same case, also pointing out that Grant “never stopped prosecutions of guilty parties and was often insistent about having them prosecuted.”

Still, Grant might bear some responsibility for the people he chose and the haphazard way he went about it. “He wrongly assumed that the skills that had made him successful in one sphere of life would translate intact into another,” Chernow acknowledges. “He entered into no consultative process, engaged in no methodical vetting of people and sent up no trial balloons to test candidates.”

Grant’s reputation as president would pay the price for many years to come.

WATCH: Grant's Troubled Presidency

With his election in 1868, Grant inherited from President Andrew Johnson a nation in turmoil. Johnson, who had been impeached by Congress but avoided conviction by a single vote, impeded the Reconstruction of the defeated South and fought attempts to extend the full rights of citizenship to formerly enslaved African Americans. As the first president after the Civil War, writes Elizabeth R. Varon, professor of American history at the University of Virginia, “Johnson did more to extend the period of national strife than he did to heal the wounds of war.”

That job would fall to U.S. Grant. His record would be far from perfect but, according to recent biographers, he deserves credit for several major achievements:

Preserving the Union and preventing a second Civil War were high on Grant’s agenda, and that outcome was by no means assured when he took office. While not as accommodating to Southern interests as Andrew Johnson, Grant oversaw the readmission of the Confederate states into the Union and took a far less punitive approach to the defeated Confederacy than other presidents might have.

In 1869, just months into his presidency, Grant invited his Confederate counterpart, Robert E. Lee, to meet in the White House. By the middle of 1870, all of the former Confederate states had made the required concessions and been readmitted to the Union. In 1872, Grant signed the Amnesty Act, which restored the voting rights and right to hold office of all but a few hundred former Confederates.

While the 13th amendment to the Constitution had granted freedom to the former slaves, and the 14th amendment had recognized them as citizens, roughly 4 million African Americans throughout the South still had little political power or representation when Grant took office. In his inaugural address and from that day forward, Grant pushed for a 15th amendment, which would guarantee federal and state voting rights to all male citizens regardless of “race, color or previous condition of servitude.”

Most dramatically, Grant used both federal troops and the newly established Justice Department to fight terrorism against Southern blacks, particularly by the Ku Klux Klan, which had grown into a large and formidable force in the years after the Civil War. “By 1872, under Grant’s leadership,” Chernow writes, “the Ku Klux Klan had been smashed in the South,” although another group of the same name would emerge in 1915.

“To him, more than to any other man, the Negro owes his enfranchisement,” Frederick Douglass remarked after Grant’s death. “When red-handed violence ran rampant through the South, and freedmen were being hunted down like wild beasts in the night, the moral courage and fidelity of Gen. Grant transcended that of his party.” Chernow concludes that, “Grant deserves an honored place in American history, second only to Lincoln, for what he did for the freed slaves.”

READ MORE: When Did African Americans Get the Right to Vote?

When Frederick Douglass praised Grant’s efforts on behalf of African Americans, he added that “the Indian is indebted [to Grant] for the humane policy adopted toward him.” By the time of Grant’s inauguration, wars between Native Americans, white settlers and the U.S. Army had been going on for decades, particularly in the expanding western U.S. Some prominent politicians and military leaders made no secret of their desire to rid the country of certain tribes by any means necessary. General William Tecumseh Sherman spoke favorably of exterminating the “men, women, children” of the Sioux, and Nevada Congressman Thomas Fitch, in a House floor debate, called for the “extinction” of Apaches.

In an address to Congress in 1869, Grant argued that “a system which looks to the extinction of a race is too horrible for a nation to adopt without entailing upon itself the wrath of all Christendom.” While his proposed solution—“placing all the Indians on large reservations, as rapidly as it can be done”—hardly seems enlightened today, he also insisted on “giving them absolute protection there.”

Grant appointed a Native American, General Ely S. Parker, as his commissioner of Indian Affairs. He also set about to reform the notoriously corrupt system that licensed traders to do business with—and often cheat—the tribes, asking respected religious groups, starting with the Quakers, to nominate worthy candidates for those positions.

As a long-term goal, Grant favored extending full citizenship to Native Americans, an injustice that wouldn’t be addressed until 1924. “Grant saw absorption and assimilation as a benign, peaceful process, not one robbing Indians of their rightful culture,” Chernow writes. “Whatever its shortcomings, Grant’s approach seemed to signal a remarkable advance over the ruthless methods adopted by some earlier administrations.”

READ MORE: Bankrupt and Dying of Cancer, Ulysses S. Grant Waged His Greatest Battle

Ironically, for a man whose administration was marked by nepotism, cronyism and graft, Grant became a leading voice for reforming the political patronage system. At the time, elected officials could dole out government jobs, regardless of the person’s qualifications, to reward supporters or in return for kickbacks. In 1871, Grant pushed for civil service legislation, and the following year appointed the first Civil Service Commission. Its aim was to replace patronage with competitive exams and other initiatives to ensure that the people who won federal jobs were actually qualified to do them.

Unfortunately, the experiment in good government would last only two years. Many legislators resented having to give up one of their most lucrative perks, so in 1874 Congress failed to fund the commission, ending its work. Some historians now question whether Grant gave up the fight too easily, but George William Curtis, a respected reformer who had chaired the commission, argued that Grant’s capitulation was “the surrender of a champion who had honestly mistaken both the nature and the strength of the adversary and his own power of endurance.”

EXPLORE: Ulysses S. Grant: An Interactive Map of His Key Civil War Battles

Grant left the presidency in March 1877. Urged on by his wife, among others, he considered a third term, which would have been unprecedented—but still legal. “Painfully aware of his mistakes as president,” Chernow writes, “Grant fantasized about reentering the White House to correct those errors and redeem his reputation.” However, that was not to be. At the Republican nominating convention in June 1880, Grant narrowly lost to James A. Garfield, who went on to win the presidency.