Before the speeches, a choir sang as attendees photographed a large panel emblazoned with one of Jackson’s mantras “keep hope alive”.
A blue-lit image of Jackson was projected on a giant screen behind an altar.
Jackson, who died on February 17, was a close associate of Martin Luther King jnr in the 1960s and remained a prominent voice of African Americans on the national stage for more than six decades.
In 1960, he participated in his first sit-in, in Greenville, South Carolina, and then joined Alabama’s Selma-to-Montgomery civil rights marches in 1965, where he caught King’s attention.
Jackson, a Baptist minister, later emerged as a mediator and envoy on several notable international fronts.
He became a prominent advocate for ending apartheid in South Africa and in the 1990s served as presidential special envoy to Africa for Bill Clinton.
Missions to free US prisoners took him to Syria, Iraq and Serbia.
He founded the Rainbow Push Coalition, a Chicago-based non-profit organisation focused on social justice and political activism, in 1996.
He is survived by his wife and six children.
– Agence France-Presse