<P> The murder of the activists sparked national outrage and an extensive federal investigation , filed as Mississippi Burning ( MIBURN ) , which later became the title of a 1988 film loosely based on the events . After the state government refused to prosecute , in 1967 the United States federal government charged 18 individuals with civil rights violations . Seven were convicted and received relatively minor sentences for their actions . Outrage over the activists ' disappearances helped gain passage of the Voting Rights Act of 1965 . </P>
what was the larger effect of the deaths of the civil rights workers in mississippi
passage of the Voting Rights Act of 1965