WASHINGTON — Sen. Daniel Inouye, the second-longest serving senator in U.S. history, was remembered Thursday as a man who gallantly defended his country on the battlefield and gracefully sought to better it during the 50-plus years he represented his beloved state of Hawaii.

Colleagues and aides lined the Capitol rotunda five deep to say farewell. The rare ceremony demonstrated the respect and good will he generated over the years. Only 31 people have lain in the Capitol rotunda; the last was former President Gerald R. Ford nearly six years ago. The last senator who died in office and was accorded the honor was Democrat Hubert Humphrey of Minnesota, in 1978.

“Daniel Inouye was an institution, and he deserved to spend at least another day in this beautiful building to which he dedicated his life,” said Senate Majority Leader Harry Reid, D-Nev....