1. Harry S. Truman (D)
Truman came into power following FDR's death, and rapidly ended WWII by deploying nuclear bombs against Japan, almost certainly saving tens of thousands of American and Japanese lives given the extreme ferocity and refusal to surrender of the Japanese throughout WWII. Truman, after ending WWII, rebuilt Europe through the Marshall Plan and as a result secured long-lasting friendships with many European nations, and built many more US friendships with some of the United States' closest allies, such as Israel, South Korea, and Japan. Truman also began the desegregation of the military by ending racial discrimination through Executive Order 9981.
2. Lyndon B. Johnson (D)
Johnson established the Medicare and Medicaid programs, defeated communism in Thailand, and signed into law the Civil Rights Act of 1964. Johnson also supported US allies Israel and Thailand.
3. John F. Kennedy (D)
Kennedy signed into law executive orders 11063 and 10925, both anti-discrimination measures, and signed into law the Equal Pay Act of 1963.
4. Grover Cleveland (D)
Cleveland sent in the military to undo president Arthur's violation of the treaties with the Winnebago and Crow Creek tribes, Arthur having opened four million acres of their land in the Dakota territory to white settlement. Military expansion and modernization was also important under Cleveland's administration,
5. Calvin Coolidge (R)
Coolidge supported racial equality and did much to help minorities, pushing for anti-lynching legislation, signing the Indian Citizenship Act granting citizenship to Amerindians on reservations, and supporting the Balfour declaration.
6. James Madison (D/R)
Madison was one of the only early presidents to make any effort to protect the rights of the Amerindians, ordering the military to protect indigenous lands from white settlers.
7. James A. Garfield (R)
James Garfield supported and furthered the rights of blacks and managed to make few poor policy decisions.
8. Thomas Jefferson (D/R)
Jefferson recognized Natives as being equal to whites, freed his slaves, won the First Barbary War, and secured the Louisiana Purchase.
9. Theodore Roosevelt (R)
Roosevelt worked towards desegregation, destroyed monopolies, extended protections for the environment, assured justice for amerindians cheated by the Indian Agency, and increased the United States' naval power to be second only to Britain.
10. Richard Nixon (R)
Though he is mostly remembered for ordering illegal activity against his political rivals, Nixon forced North Vietnam into a peace treaty, ended US involvement in the Vietnam war, brought the American prisoners of war home, created the Environmental Protection Agency, presided over the landing of the first men on the moon, and continued to enforce desegregation, implementing large-scale racial integration of schools in the south.
11. Rutherford B. Hayes (R)
Hayes ended the prior system of assigning offices to the president's supporters and instead based on merit, made pro-amerindian moves such as preventing the War Department from taking over the Bureau of Indian Affairs and giving the Ponca tribe compensation for their land rights, and also returned the South to home rule.
12. Ulysses S. Grant (R)
Grant supported native rights more than most previous presidents, though that's not saying much, but on the contrary he also vetoed a bill that would have protected the Bison that Amerindians hunt. Grant also spoke out against voter intimidation of blacks in the south and supported civil rights significantly more than Andrew Johnson had.
13. William McKinley (R)
McKinley made numerous economic accomplishments, preserving the gold standard and raising tariffs to protect American workers from foreign competition.
14. William Howard Taft (R)
Though Roosevelt is often credited with the destruction of monopolies, Taft busted twice as many trusts as Roosevelt had, he also abrogated the Russo-American Treaty of 1832. Unfortunately, Taft refused to appoint African Americans to federal jobs and was generally weak in terms of civil rights.
15. Abraham Lincoln (R)
Lincoln freed the slaves through his emancipation proclamation, though he also made numerous dubious decisions against the Union state of Maryland and his armies committed several war crimes. Nonetheless, he held the Union together.
16. Bill Clinton (D)
Clinton's administration was notable for leaving the country with an economic surplus of around 236,000,000,000 USD and stayed loyal to US allies. Unfortunately, he also involved the US in the Kosovo war and was responsible for the idiotic Federal Assault Weapons Ban.
17. James K. Polk (D)
Polk supported US ally Texas and defeated Mexico in the Mexican-American war, furthering US expansion into the west.
18. John Quincy Adams (D/R)
President JQA funded a number of public works, such as the United States Naval Observatory and various roads and expanded the US further west, as well as being a prominent opponent of slavery and supporter of consensual mutual agreements with natives in place of the murderous Jingoism of most presidents of his time.
19. George H. Bush (R)
Bush 1 signed into law the Americans with Disabilities Act of 1990, and the Clean Air Act Amendments of 1990.
20. Benjamin Harrison (R)
Benjamin Harrison didn't accomplish much, but didn't make too many poor policy decisions either, and handled several situations he was faced with, such as the Canadian-American fishing dispute in the Aleutian islands, with tact and avoided causing international incidents.
21. Ronald Reagan (R)
On the positive side, Reagan extensively supported the military, reviving the B-1 Lancer program and developing the MX Missile program, as well as leading a strong response to the Soviet downing of Korean Air Lines Flight 007. Unfortunately, president Reagan halted US arms sales to Taiwan and, more importantly, opposed the Civil Rights Act of 1964, the Voting Rights Act of 1965, fair housing legislation, supported segregated universities, and at every turn was happy to sacrifice the rights of blacks and other minorities to gain the white vote until he was forced by his own congress or party to give in.
22. Herbert Hoover (R)
Hoover's presidency was overshadowed by the Great Depression. He didn't accomplish much himself, but had a decent foreign policy at least, largely not intervening in the internal affairs of Latin American nations as well as supporting the Balfour declaration.
23. James Monroe (D/R)
Monroe created the Monroe doctrine, under which America would fight colonization and support independence for nations of the Americas. James Monroe was also a slave owner but did not make any significant setbacks for abolitionism during his career.
24. Dwight D. Eisenhower (R)
Eisenhower overthrew the democratically elected government of Iran and Guatemala, while not supporting long-time US allies Britian, France, and Israel in their war against Egypt, but also created the interstate highway system and established a number of important scientific agencies and programs such as NASA, DARPA, and the National Defense Education Act.
25. George W. Bush (R)
George Bush responded to the 9/11 attacks very poorly by diverting US forces to fight a war against Iraq, which had no association with the attacks or Al Qaeda, and poorly handled Hurricane Katrina; Bush did contribute significant aid to Africa and supported South Sudan.
26. John Tyler (none)
John Tyler signed a few treaties, such as the Treaty of Wanghia and Webster–Ashburton Treaty, which had positive influences, but didn't have many great accomplishments, and was expelled from his own party when he took office.
27. Zachary Taylor (W)
Taylor had vague political beliefs and was elected for being a national hero. Taylor didn't do much and didn't solve the issues facing him relating to slavery and the admission of the territory gained in the Mexican-American war.
28. William Harrison (W)
Poor Harrison lived only 30 days into his presidency, he of course accomplished nothing during this 30 day period, with the exception of delivering the longest inaugural address in history.
29. James Buchanan (D)
James Buchanan was a weak leader who alienated both Democrats and Republicans and who's weak leadership contributed to the civil war.
30. Franklin D. Roosevelt (D)
In an anticonstitutional action, Franklin Roosevelt raised extreme taxes on guns attempting to infringe on the right of the people to keep and bear them. Roosevelt also forced thousands of people into internment camps based on their ethnicities, failed to support the UK directly against Germany for several years, refused to take in Jews who were persecuted in Germany, and used the IRS against his political opponents. FDR's economic policy was well-made, at least, and FDR's fight against recession was a success.
31. Gerald Ford (R)
The only president who made it into office without ever being voted for by anyone for the office of either president or vice president performed about as well as you'd expect; Despite overwhelming support from the senate, president Ford vetoed a bill which would halt all military aid of Turkey following a recent neocolonialist invasion of Cyprus, while simultaneously refusing to support US ally Israel and again favoring the aggressor, Egypt. Ford's leadership lead to a Democrat-controlled congress which pulled out US support for South Vietnam, leading to a North Vietnamese invasion and the loss of a war which was widely thought to have already been won.
32. Jimmy Carter (D)
The one-term Carter freakshow was defined by blind trust in foreign powers like the Soviet Union and North Korea, massive blunders in the Iran hostage crisis, and state-sponsored terrorism in Afghanistan. Jimmy Carter is still alive and embarrassing himself, spending his post-presidency years supporting terrorist groups like Hamas and claiming that Kim Jong Un is a rational individual who wants peace.
33. Barack Obama (D)
Obama's weak leadership caused the collapse of race relations and the rise of the racist Black Lives Matter movement. Obama doubled the national debt, had a cowardly, dishonest stance on Islam and Islamic terrorism, destabilized Syria and Libya causing the refugee crisis, failed US allies like South Korea, Israel, and South Sudan through cowardice, hostility, and incompetence and was complicit in a number of dubious actions such as operation fast and furious (in which drug cartels were intentionally sold weapons) and numerous infringements on the privacy and security of the American people. Obama is not the worst president, however, as he also had a few good accomplishments, such as ending the sanctions against Myanmar, legalizing gay and lesbian marriage nationwide, and expanding medicaid and medicare through his Obamacare program (though Obamacare also included disastrous failures).
34. Andrew Johnson (D)
Johnson vetoed the Civil Rights Act of 1866 and the Fourteenth Amendment, attempting to stop the furthering of rights for black Americans during his presidency.
35. Millard Fillmore (W)
Fillmore signed the Fugitive Slave Act and was a supporter of the Compromise of 1850, allowing slavery in the newly gained territories obtained during the Mexican-American war.
36. Franklin Pierce (D)
Pierce upheld the Fugitive Slave Act and the The Kansas–Nebraska Act of 1854, which caused a civil conflict within Kansas between pro- and anti-slavery factions which contributed to the civil war.
37. Woodrow Wilson (D)
Woodrow Wilson's presidency was very mixed. On one hand, Wilson stopped desegregation dead in it's tracks and undid much of the work of Taft and Roosevelt, but on the other, Wilson oversaw the implementation of the 19th amendment, which granted women the right to vote, and also supported the Balfour declaration (albeit reluctantly). Wilson's administration certainly did plenty of good, but it was far overshadowed by the bad he did.
38. Warren G. Harding (R)
Harding's administration was notoriously corrupt, though he was not himself complicit in the corruption. Harding pardoned many political prisoners, condemned lynchings, and supported the Balfour Declaration, but Harding did little in practice to support desegregation, make decisions on the glaring issue of US relations with Bolshevik Russia, or get much of anything important done, for that matter.
39. Chester Arthur (R)
A machine politician who replaced Garfield, Chester Arthur did virtually nothing, except for signing the Chinese Exclusion Act, which stopped Chinese people from immigrating. Arthur also violated treaties made with Amerindian tribes and allowed white settlers to encroach on their territories.
40. Martin Van Buren (D/R)
Van Buren was largely an accessory to the Jackson presidency, following his policies for the most part. Van Buren forcibly removed around 20,000 Cherokee and continued the murderous Second Seminole War.
41. John Adams (F)
The Adams administration created the Sedition Act of 1798, an anticonstitutional law which forbid people from criticizing the government, and the Naturalization Act of 1798, which made it harder for immigrants to become citizens specifically because immigrants were voting Democratic-Republican rather than Federalist.
42. Andrew Jackson (D)
Mistreatment of the Native Amerindians has no better example than the founder of the Democrat Party himself, Andrew Jackson. For a perfect example of his complete lack of respect for anyone who wasn't a white American, one needn't look any further than the First Seminole War, in which Jackson (at the time a general) invaded Spanish Florida to chase fleeing slaves and attacked the native Seminoles, murdering two British civilians in the process. Once he obtained the Presidential office, Jackson amplified his needless cruelty towards the indigenous people, forcing tens of thousands of them out of their land and across the Mississippi, with thousands dying along the way. Andrew Jackson is also the only president to explicitly defy the supreme court, going against the decision of Worcester v. Georgia in 1832.