Washington (CNN) - Colleagues of Sen. Robert Byrd of West Virginia mourned his death as family and friends planned his funeral.
Byrd, the longest-serving member of the U.S. Congress, died Monday at the age of 92.
West Virginia Gov. Joe Manchin, a Democrat like Byrd, will appoint his replacement.
Read the reactions of Byrd's colleagues after the jump.
– Sen. Jay Rockefeller, D-West Virginia
"It has been my greatest privilege to serve with Robert C. Byrd in the United States Senate. I looked up to him, I fought next to him, and I am deeply saddened that he is gone. He leaves a void that simply can never be filled. But I am lifted by the knowledge of his deep and abiding faith in God, I have joy in the thought of him reunited with his dear (late wife) Erma, and I am proud knowing that his moving life story and legacy of service and love for West Virginia will live on.
Senator Byrd came from humble beginnings in the southern coalfields, was raised by hard-working West Virginians, and triumphantly rose to the heights of power in America. But he never forgot where he came from nor who he represented, and he never abused that power for his own gain."
–U.S. Senate Republican Leader Mitch McConnell
"Sen. Byrd combined a devotion to the U.S. Constitution with a deep learning of history to defend the interests of his state and the traditions of the Senate. We will remember him for his fighter's spirit, his abiding faith,
and for the many times he recalled the Senate to its purposes.... We are glad to know that Senator Byrd and his beloved Erma are reunited. We extend our deepest sympathies to the entire Byrd family."
–Sen. Patrick Leahy, D-Vermont
"No senator came to care more about the Constitution or to be a more effective defender of our constitutional government than the senior senator from West Virginia. He was a senator's senator.... I know him as a mentor and a friend. I was honored to stand with him and fight against assaults on the Constitution and against an unnecessary and costly war in Iraq.
He was a self-educated man who learned much throughout his life and had much to teach us all. He was a symbol of West Virginia, he was an outstanding senator, and he was extraordinary American."
–Sen. Jeff Sessions, R-Alabama
"It is a sad day for all of us. There was no one who loved the institution of the Senate more, and no one who was a better student of it."
– CNN Senate Producer Ted Barrett contributed to this report.