The body of Senator Edward "Ted" Kennedy, who died Tuesday after a battle with cancer, is lying in repose at the John F. Kennedy Presidential Library in Boston, allowing mourners to pay their respects to the Lion of the Senate.

Kennedy, who passed away Tuesday night at 77, is lying in repose through Friday.

Family members, including the late senator's wife Vicki Kennedy, greeted mourners filing past the casket. Visitors can also sign condolence books during normal museum hours.

Thousands waited in line outside to pay their respects.

"He was very open-minded and he was putting us all in the right direction. He brought people together," said mourner Tamara DeMaio. "He just wanted to make the world a better place and make a difference, and I don't feel as comfortable without him in Congress anymore."

Kennedy's body arrived at the library with a motorcade bearing 85 family members, and passed by the sites that were significant to him, including the church where he eulogized his mother.

A memorial service is planned for Friday night, with a private funeral family mass set for Saturday at Our Lady of Perpetual Help Basilica.

President Barack Obama will deliver the eulogy and Mayor Michael Bloomberg will be among those in attendance.

Kennedy will then be laid to rest at Arlington National Cemetery, where his slain brothers John and Robert are also buried.

Across the city and the nation, Americans are mourning the loss of one of the most influential senators in history.

The Senate desk used by Kennedy, and earlier by his brother John, is currently covered by a black shroud and a vase of white roses.

Flags are also being flown at half-staff at all federal buildings.

Meanwhile, Kennedy's death is leaving behind an open Senate seat in Massachusetts for the first time in nearly a half a century.

State law requires a special election, with a vote scheduled sometime between January and February of next year.

In a recent letter to state lawmakers, Kennedy said the law should be changed to allow the governor to name an interim appointee.

There is a list of candidates interested in running for the seat –including his nephew, former Congressman Joseph P. Kennedy II, seen left. Other Democratic contenders include Congressmen Stephen Lynch and James McGovern.