A white hearse carrying Parks's body travelled early on Wednesday from the Charles H Wright Museum of African American History in Detroit to the church where her funeral was to be held later in the morning.
Dozens of people holding pictures of Parks crowded around the hearse and shouted "We love you" as it began moving.
Claudette Bond, 62, was the first person in line outside the glass doors of Greater Grace Temple, waiting since 6pm (local time) on Tuesday for one of 2000 public seats for Parks' funeral.
She had spent the night in a lawn chair despite the temperature dipping below 40 degrees.
By 7.30am (local time), the line for the funeral extended more than two blocks west of the church with about 800 people waiting.
"This will never happen again. There will never be another Rosa Parks," said Moses Fisher, who was one of the hundreds in line hoping to get a seat in the church.
The Reverend Jesse Jackson was to deliver Parks's eulogy.
"This will never happen again. There will never be another Rosa Parks"
Among those planning to attend the service were former president Bill Clinton, his wife, US Senator Hillary Rodham Clinton, Michigan Governor Jennifer Granholm, members of the Congressional Black Caucus, civil rights leaders and other dignitaries. Aretha Franklin was to sing.
The church holds 4000 people, even more than the Washington church where President George Bush and wife Laura attended Parks's memorial service.
Parks was 92 when she died on 24 October in Detroit. Nearly 50 years earlier, as a 42-year-old tailor's assistant in Montgomery, Alabama, she was arrested and fined $10 plus $4 in court costs for refusing to give up her seat to a white man on a Montgomery city bus.
Her action on 1 December 1955, triggered a 381-day boycott of the bus system led by the Reverend Martin Luther King Junior.
The US Supreme Court ruled in December 1956 that segregated seats on city buses were unconstitutional, giving momentum to the battle against laws that separated the races in public accommodations and businesses throughout the South.
But Parks and her husband Raymond were exposed to harassment and death threats in Montgomery, where they also lost their jobs. They moved to Detroit with Rosa Parks's mother, Leona McCauley, in 1957.
Parks coffin had lain in state in
the US Capitol
Parks held a series of low-paying jobs before US Republican John Conyers hired her in 1965 to work in his Detroit office. She remained there until 1987.
Parks was initially going to be buried in a family plot in Detroit's Woodlawn Cemetery, next to her husband and mother.
But Swanson Funeral Home officials confirmed on Tuesday that Parks would be entombed in a mausoleum at the cemetery and the bodies of her husband and mother would also be moved there.