Question: Three civil rights activists were working on what project when they were abducted and murdered in June of 1964?

Context articles: Freedom Summer
Die-in
Alton Wayne Roberts
Florence Mars
Chinese Human Rights Defenders
Bob Kunst
Murders of Chaney, Goodman, and Schwerner
Specialized Criminal Court (Saudi Arabia)
Greyhound Bus Station (Montgomery, Alabama)
Edgar Ray Killen

Freedom Summer, or the Mississippi Summer Project, was a volunteer campaign in the United States launched in June 1964 to attempt to register as many African-American voters as possible in Mississippi.
 Blacks had been cut off from voting since the turn of the century due to barriers to voter registration and other laws.
 The project also set up dozens of Freedom Schools, Freedom Houses, and community centers in small towns throughout Mississippi to aid the local black population.
A die-in, sometimes known as a lie-in, is a form of protest in which participants simulate being dead.
 Die-ins are actions that have been used by a variety of protest groups including animal rights activists, anti-war activists, human rights activists, AIDS activists, gun control activists and environmental activists.
 Often, protestors occupy an area for a short time instead of being forced to leave by the police.
Alton Wayne Roberts (April 6, 1938 – September 11, 1999) was a Klansman convicted of depriving slain activists Michael Schwerner, Andrew Goodman and James Chaney of their civil rights in 1964.
 He personally shot two of the three civil rights workers before his accomplices buried their bodies in a dam.
Florence Mars (January 1, 1923 – April 23, 2006) was an American civil rights activist and author best known for her book "Witness in Philadelphia" about the murder of three civil rights activists in Mississippi.
China Human Rights Defenders (CHRD) is a non-government organization of domestic and overseas Chinese human rights activists and groups.
 The organization is headquartered in Washington DC.
 Its objective is to provide assistance to both human rights activists and victims of rights abuses, as well as to monitor developments in human rights and rule of law.
 CHRD supplies grants to Chinese human rights activists, as well as legal training and assistance.
Bob Kunst (a.k.a. Robert Kunst) is one of America's leading human rights and civil rights activists, he is also known as an anti-Nazi and anti-KKK activist.
 Born in 1941, a native of Miami Beach, Florida, Kunst spent much of his adult life since the early 1960s in civil rights activism for African-Americans, Women, LGBT people, especially in the 1976 Miami-Dade County Ordinance for Gay Rights which was passed to protect the civil rights of Lesbians and Gays, and Bisexuals, and later Kunst was involved in activism for people with AIDS.
 Kunst was active to opposed Save Our Children, a Dade County, Florida voter-approved county initiative supported by singer Anita Bryant and her then-husband Bob Green, the initiative repealed the previous anti-discrimination ordinances Kunst fought for in employment, especially in public education teaching, and housing based on Sexual Orientation, but this law was eventually repealed by the state Supreme Court of Florida in 2010.
 Kunst later became more involved in Gay Rights activism in the United States ever since.
 As a Democratic Party politician, Kunst unsuccessfully campaigned against Republican Bob Graham in the 1986 United States Senate elections in Florida.
 Kunst also ran unsuccessfully in the 2010 United States House of Representatives Election, this time as an unaffiliated independent, against incumbent Rep. Debbie Wasserman Schultz, a Democrat, in the State of Florida.
 Kunst volunteered for the Hillary Rodham Clinton 2008 U.S. presidential campaign in his hometown of Miami, Florida.
 Kunst was president (1991-2001) of Shalom International, a Jewish group combating global Neo-Nazism and Neo-fascism movements.
 And he was a co-founder of the Oral Majority in 1982, the Liberal and secular counter-protest group of the Religious Right organizations Moral Majority and later the Christian Coalition.
 Outside of political causes, Kunst worked in marketing for the Miami Toros professional soccer team in the 1970s.
The murders of Chaney, Goodman, and Schwerner, also known as the Freedom Summer murders, the Mississippi civil rights workers' murders or the Mississippi Burning murders, involved three activists that were abducted and murdered in Neshoba County, Mississippi in June 1964 during the Civil Rights Movement.
 The victims were Andrew Goodman and Michael "Mickey" Schwerner from New York City, and James Chaney from Meridian, Mississippi.
 All three were associated with the Council of Federated Organizations (COFO) and its member organization the Congress of Racial Equality (CORE).
 They had been working with the Freedom Summer campaign by attempting to register African Americans in Mississippi to vote.
 This registration effort was a part of contesting over 70 years of laws and practices that supported a systematic policy of disenfranchisement of potential black voters by several southern states that began in 1890.
The Specialized Criminal Court (SCC) (Arabic: المحكمة الجزائية المتخصصة‎ ‎ ) is a non-Sharia court created in Saudi Arabia in 2008 that tries suspected terrorists and human rights activists.
 On 26 June 2011, the court started trials of 85 people suspected of being involved in Al-Qaeda in the Arabian Peninsula and the 2003 Riyadh compound bombings and in September 2011 another 41 al-Qaeda suspects appeared in the court.
 In the same year, the court held trial sessions of human rights activists, including co-founder Mohammed Saleh al-Bejadi of the Saudi Civil and Political Rights Association (ACPRA) and Mubarak Zu'air, a lawyer for long-term prisoners, and Khaled al-Johani, who spoke to BBC Arabic Television at a protest in Riyadh, thus becoming known as "the bravest man in Saudi Arabia".
 The court convicted 16 of the human rights activists to sentences of 5–30 years' imprisonment on 22 November 2011.
The Greyhound Bus Station at 210 South Court Street in Montgomery, Alabama, was the site of a violent attack on participants in the 1961 Freedom Ride during the Civil Rights Movement.
 The May 1961 assaults, carried out by a mob of white protesters who confronted the civil rights activists, "shocked the nation and led the Kennedy Administration to side with civil rights protesters for the first time."
Edgar Ray "Preacher" Killen (born January 17, 1925) is a former Ku Klux Klan organizer who planned and directed the murders of James Chaney, Andrew Goodman, and Michael Schwerner, three civil rights activists participating in the Freedom Summer of 1964.
 He was found guilty in state court of three counts of manslaughter on June 21, 2005, the forty-first anniversary of the crime, and sentenced to 60 years in prison.
 He appealed against the verdict, but the sentence was upheld on January 12, 2007, by the Mississippi Supreme Court.