Dion’s main focus was to get people to vote, both locally, and higher up. Diamond began doing sit-ins at the age of 15, in Petersburg, Virginia with groups and by himself. He would reportedly take a stool at segregated counters and wait to be served until the managers called the Petersburg Police Department, at which point he would run for the door. Notably, he was also a part of the sit-in movement in Washington, DC in the 1960s. At the age of 19, he engaged in protests at People's Drug Store at Lee Highway and Old Dominion Drive in Arlington Virginia. Following this particular sit-in, Diamond and others moved the sit-in to the Drug Fair at 5401 Lee Highway, where they were also refused service. One of the more noted sit-in's Dion was part of occurred in Arlington, Virginia at a drugstore on June 9, 1960. Diamond and his classmates at Howard University formed a group called the Nonviolent Action Group from which he participated in protests around Arlington. Dion also protested to integrate interstate transportation by joining the second wave of freedom riders after hearing of the Trailway’s bus burning. Dion was a field secretary for the Student Non-Violent Coordinating Committee in Mississippi and Louisiana from 1961-63. Diamond was arrested on more than 30 different occasions. On one occasion, on the anniversary of the Greensboro sit-ins, he made his return to speak at Southern University in Baton Rouge, Louisiana where he was arrested under the Sedition law The arrest at Southern University was significant as his bail was raised to $12,000 USD and he was charged with “criminal anarchy”. Another activist, Kwame Ture, led a sit-in at Attorney GeneralRobert Kennedy's office in an effort to secure Diamond's release. Prior to this arrest, at the Southern University, on January 31 YEAR, Diamond led a rally in which he told the gathered students to walk out of their classes in the afternoon if they did not have the courage to continue a week-long protest. He then led over a hundred students through several buildings shouting "We want freedom!" and "Segregation is over!". He would then later be arrested and charged with vagrancy and trespassing. Diamond has alleged in interviews that officers at the jail instructed the other inmates that Diamond was a "trouble maker" and they should "give him a hard time" to potentially get time off for good behavior. Carmichael recounted an experience he had with Diamond and an armed cop in which Diamond reportedly yelled at the cop until he left the jail cell;
Personal life
After years of activism, Diamond transferred to the University of Wisconsin where he studied sociology and the post-Civil War period of Reconstruction, and later earned a graduate degree in education from Harvard. As of 2019, Dion works in finance and lives in Washington D.C. he continues to protest and speak publicly in hopes to inspire the next generations speak up and against racial inequality.