The liberal icon who served nearly 47 years in the Senate was honored for his faith, the quality of his character, his love of family, friends and country, and the depth of his contributions.
In addition to members of the Kennedy family, Vice President Joe Biden, and both Republicans and Democrats from the Senate are paying tribute to the late senator at the service.
The Democratic senator died Tuesday at the age of 77. An estimated 50,000 people filed past his flag-draped coffin on Thursday and Friday to pay their last respects.
On Saturday, there will be a funeral Mass in Boston with President Barack Obama delivering a eulogy, before the senator is to be buried at Arlington National Cemetery in Washington.
Although Kennedy was a liberal stalwart, lawmakers who served with him, and all living former U.S. presidents, have praised the late senator for his ability to reach across party lines to pass health care, civil rights and education legislation.
Three former presidents --Jimmy Carter, Bill Clinton and George W. Bush -- are expected to attend the funeral.
British Prime Minister Gordon Brown will not be attending the funeral, but wrote in Friday's Boston Globe that Kennedy is being mourned as a "great internationalist" who inspired social progress in every country.
Tributes also have come from other world leaders, highlighting Kennedy's dedication to human rights and his work to end apartheid in South Africa.
On Thursday, thousands of people lined streets to catch a glimpse of the motorcade that brought the coffin of Senator Kennedy to the museum from his home in Hyannis Port on Cape Cod.Some information for this report was provided by AP.