The four living former U.S. presidents, Bill Clinton, George H.W. Bush, Jimmy Carter and Gerald Ford attended the funeral along with dozens of current and former world leaders including former British Prime Minister Margaret Thatcher and former Soviet President Mikhail Gorbachev.
Police closed city streets as some 50 secure motorcades carrying dignitaries from around the world converged on the Cathedral prior to the arrival of the funeral procession.
Former Sen. John Danforth, R-Mo., the newly named U.S. ambassador to the United Nations and an Episcopalian minister, officiated at the service.
President Bush, his father, Thatcher and former Canadian Prime Minister Brian Mulroney were invited to speak by the Reagan family.
"We have lost a great president a great American and a great man, and I have lost a dear friend," Thatcher said in a tribute taped months ago when, after a series of strokes, doctors advised her to give up speaking in public. She sat in the audience while her tape was played.
"He sought to mend America's wounded spirit, to restore the strength of the free world, and to free the slaves of communism," Thatcher said. "These were causes hard to accomplish and heavy with risk."
Thatcher said that America and the world are thankful for Mr. Reagan's legacy.
"With the lever of American patriotism, he lifted up the world," Thatcher said. "And so today the world -- in Prague, in Budapest, in Warsaw, in Sofia, in Bucharest, in Kiev and in Moscow itself -- the world mourns the passing of the Great Liberator and echoes his prayer 'God Bless America.'"
Former Pres. George H.W. Bush said he learned more from President Reagan than any other person he met in public life.
"I learned kindness; we all did. I also learned courage; the nation did," Mr. Bush said.
"Politics can be cruel, uncivilized," he added. "Our friend was strong and gentle."
Supreme Court Justice Sandra Day O'Connor and Rabbi Harold Kuchner gave readings, after which Irish tenor Dr. Ronan Tynan sang Ave Maria and Amazing Grace.
O'Connor read portions from American Pilgrim leader John Winthrop's "City on a Hill" sermon, a theme often echoed by Mr. Reagan in his presidential speeches. The sermon says that America is an exceptional land that will be favored of God and serve as an example to the world if its people live righteously.
"For we must consider that we shall be as a city upon a hill," read O'Connor. "The eyes of all people are upon us."
President George W. Bush reminded the nation that Mr. Reagan had made a public farewell a decade ago, when he was first diagnosed with Alzheimer's disease.
"It has been ten years since he said his own farewell, yet it is still very sad and hard to let him go," Mr. Bush said. "Ronald Reagan belongs to the ages now, but we preferred it when he belonged to us."
President Bush also recounted the major events of Reagan's life including his birth in a small town in Illinois, his Hollywood career, his tenure as governor, and finally his election to the presidency and emergence as a world leader.
"Ronald Reagan's moment arrived in 1980. He came out ahead of some very good men, including one from Plains and one from Houston," the president said, alluding to Reagan's 1980 election victory over his father George H.W. Bush and then President Carter. "What followed was one of the decisive decades of the century as the convictions that shaped the president began to shape the times."
President Bush also credited Mr. Reagan, the president famous for calling the Soviet Union an "evil empire," with telling the truth about communist nations and helping to bring freedom to their people.
"He was optimistic that liberty would thrive wherever it was planted, and he acted to defend liberty wherever it was threatened," President Bush said. "And Ronald Reagan believed in the power of truth in the conduct of world affairs. When he saw evil camped across the horizon he called that evil by its name."
The president, like the elder Bush, said Mr. Reagan was a man of inordinate kindness and generosity.
"Ronald Reagan carried himself, even in the most powerful office, with the decency and attention to small kindnesses that also define a good life," Mr. Bush said. "He was a courtly, gentle and considerate man, never known to slight or embarrass others."
Between Wednesday evening and Friday morning some 100,000 filed by to pay their respects to the former president as his body lay in state in the U.S. Capitol Rotunda.
Around 10:30 a.m. Friday EDT Reagan's coffin was carried from the Capitol by a U.S. military honor guard while the U.S. Army Band played Hail to the Chief and the Navy Hymn. Ceremonial artillery cannons on the Capitol grounds fired a 21-gun salute. The former president's coffin was then placed in a hearse for the procession to the National Cathedral.
At the cathedral, the Rev. John Bryson Chane, Episcopal bishop of Washington, received the former president's coffin. An honor guard carried the coffin to the nave of the building where it lay for the remainder of the funeral service.
Honorary pall bearers chosen by the Reagan family included: Michael Deaver, a close aide to Reagan during his presidency; Merv Griffin, a Hollywood producer, talk show host and friend of the family; Dr. John Hutton, a former U.S. Army general and Mr. Reagan's White House physician; Frederick Ryan Jr., chairman of the board of the Ronald Reagan Presidential Foundation and an aide during Reagan's post-presidential years; and Charles Wick, a Hollywood director and head of the U.S. Information Agency during the Reagan presidency.
At noon, military bases around the world fired cannons as part of a global 21-gun salute to honor the former president.
Following the funeral service President Reagan's coffin was carried to its hearse as the cathedral bells chimed and a military band played Hail to the Chief and God Bless America.
By 1 p.m. the funeral procession was on its way to Andrew's Air Force Base in Maryland for the flight back to California. The former president's body will be laid to rest during a sunset ceremony Friday at his presidential library in Simi Valley, Calif.