While at the University of Chicago, Sanders joined the Young People's Socialist League (the youth affiliate of the Socialist Party of America), and was active in the Civil Rights Movement as a student organizer for the Congress of Racial Equality (CORE) and the Student Nonviolent Coordinating Committee (SNCC). Under Sanders's chairmanship, the university chapter of CORE merged with the university chapter of SNCC. In January 1962, Sanders led a rally at the University of Chicago administration building to protest university president George Wells Beadle's segregated campus housing policy. "We feel it is an intolerable situation when Negro and white students of the university cannot live together in university-owned apartments," Sanders said at the protest. Sanders and 32 other students then entered the building and camped outside the president's office, performing the first civil rights sit-in in Chicago history. After weeks of sit-ins, Beadle and the university formed a commission to investigate discrimination. Joan Mahoney, a member of the University of Chicago CORE chapter at the time and a fellow participant in the sit-ins, described Sanders in a 2016 interview as "...a swell guy, a nice Jewish boy from Brooklyn, but he wasn't terribly charismatic. One of his strengths, though, was his ability to work with a wide group of people, even those he didn't agree with". Sanders once spent a day putting up fliers protesting against police brutality, only to eventually notice that a Chicago police car was shadowing him and taking them all down.  Sanders attended the 1963 March on Washington for Jobs and Freedom, where Martin Luther King, Jr. gave his "I Have a Dream" speech. That summer, he was convicted of resisting arrest during a demonstration against segregation in Chicago's public schools and was fined $25.  In addition to his civil rights activism during the 1960s and 1970s, Sanders was active in several peace and antiwar movements. He was a member of the Student Nonviolent Coordinating Committee and the Student Peace Union while attending the University of Chicago. Sanders applied for conscientious objector status during the Vietnam War; his application was eventually turned down, by which point he was too old to be drafted. Although he opposed the war, Sanders never criticized those who fought and has been a strong supporter of veterans' benefits. Sanders also worked on the reelection campaign of Leon Despres, a prominent Chicago alderman who was opposed to mayor Richard J. Daley's Democratic Party machine. During his student years he also read a variety of American and European political authors, from Thomas Jefferson, Abraham Lincoln, and John Dewey to Karl Marx and Erich Fromm.  The 39-year-old Sanders ran against incumbent Democratic mayor Gordon "Gordie" Paquette, a five-term mayor who had served as a member of the Burlington City Council for 13 years before that, building extensive community ties and a willingness to cooperate with Republican leaders in controlling appointments to various commissions. Republicans had found Paquette so unobjectionable that they failed to field a candidate in the March 1981 race against him, leaving Sanders as his principal opponent. Sanders's effort was further aided by the decision of the candidate of the Citizens Party, Greg Guma, to exit the race so as not to split the progressive vote. Two other candidates in the race, independents Richard Bove and Joe McGrath, proved to be essentially non-factors in the campaign, with the battle coming down to Paquette and Sanders.  Sanders castigated the pro-development incumbent as an ally of prominent shopping center developer Antonio Pomerleau, while Paquette warned of ruin for Burlington if Sanders was elected. The Sanders campaign was bolstered by a wave of optimistic volunteers as well as by a series of endorsements from university professors, social welfare agencies, and the police union. The final result came as a shock to the local political establishment, with the maverick Sanders winning by just 10 votes.  Sanders was reelected three times, defeating both Democratic and Republican candidates. He received 53% of the vote in 1983 and 55% in 1985. In his final run for mayor in 1987, Sanders defeated Paul Lafayette, a Democrat endorsed by both major parties. In 1986, Sanders unsuccessfully challenged incumbent Governor Madeleine Kunin (D) in her run for reelection. Running as an independent, Sanders finished third with 14.4% of the vote. Kunin won with 47%, followed by Lt. Governor Peter P. Smith (R) with 38%.  After serving four two-year terms, Sanders chose not to seek reelection in 1989. He lectured in political science at Harvard University's Kennedy School of Government that year and at Hamilton College in 1991.  In 1993, Sanders voted against the Brady Bill, which mandated federal background checks when buying guns and imposed a waiting period on firearm purchasers in the United States; the bill passed by a vote of 238-187.  In 1994, Sanders voted in favor of the Violent Crime Control and Law Enforcement Act. Sanders said he voted for the bill "because it included the Violence Against Women Act and the ban on certain assault weapons". He was nevertheless extremely critical of the other parts of the bill. Though he acknowledged that "clearly, there are some people in our society who are horribly violent, who are deeply sick and sociopathic, and clearly these people must be put behind bars in order to protect society from them", he maintained in his intervention before the House that the government's ill-thought policies played a large part in "dooming tens of millions of young people to a future of bitterness, misery, hopelessness, drugs, crime, and violence". In this same intervention, he argued that the repressive policies introduced by the bill were not addressing the causes of violence, stating that "we can create meaningful jobs, rebuilding our society, or we can build more jails".  In 2005, he voted for the Protection of Lawful Commerce in Arms Act. The act's purpose was to prevent firearms manufacturers and dealers from being held liable for negligence when crimes have been committed with their products. In 2015, Sanders defended his vote, saying: "If somebody has a gun and it falls into the hands of a murderer and the murderer kills somebody with a gun, do you hold the gun manufacturer responsible? Not any more than you would hold a hammer company responsible if somebody beats somebody over the head with a hammer."  Sanders voted against the resolutions authorizing the use of force against Iraq in 1991 and 2002, and opposed the 2003 invasion of Iraq. He voted for the 2001 Authorization for Use of Military Force Against Terrorists that has been cited as the legal justification for controversial military actions since the September 11 attacks. Sanders voted for a non-binding resolution expressing support for troops at the outset of the invasion of Iraq, but gave a floor speech criticizing the partisan nature of the vote and the George W. Bush administration's actions in the run-up to the war. Regarding the investigation of what turned out to be a leak of CIA agent Valerie Plame's identity by a State Department official, Sanders stated: "The revelation that the President authorized the release of classified information in order to discredit an Iraq war critic should tell every member of Congress that the time is now for a serious investigation of how we got into the war in Iraq and why Congress can no longer act as a rubber stamp for the President."  On November 2, 2005, Sanders voted against the Online Freedom of Speech Act, which would have exempted the Internet from the campaign finance restrictions of the McCain-Feingold Bill.

Answer this question "What other accomplishments did he achieve?" by extracting the answer from the text above.
Sanders never criticized those who fought and has been a strong supporter of veterans' benefits.