The men and women who worked with Ronald Reagan during his two terms as president are sharing their thoughts with the American public.

Heads of state and schoolchildren alike, pass under the gaze of Ronald Reagan's official portrait when they visit the White House. When you enter the main north doors and stand by the grand staircase, it seems Mr. Reagan is looking at you. The eyes in the portrait sparkle and the familiar smile is there. He is remembered for that smile, that look of a man at peace with himself.

"He was a strong leader with an uncommon gift of unbounded optimism as well as a belief in a few very important core principles to which he stuck and was thereby able to change the world," says James Baker, who joined the Reagan administration as the president's chief of staff and went on to become secretary of the treasury . During an appearance on the CBS television program Face the Nation, he recalled a day early on in Ronald Reagan's first term in office, a day when he bluntly criticized the Soviet Union.

"A lot of people in the foreign policy and national security community in Washington and New York and elsewhere started 'tut-tutting'[commenting derisively] about this 'cowboy, gunslinger, actor' who came into the presidency from California and how undiplomatic that was and how un-statesmanlike those comments were," says Mr. Baker. "Well, history proved he was right."

Those who worked with him at the White House say Mr. Reagan knew in his heart that the Soviet Union, which he called "the evil empire", was unsustainable. Secretary of State Colin Powell was his national security advisor in the final year of his second term.

"He believed, ultimately, that the Soviet Union was a failed political system and it was his role as president to help bring about the end, not to push them over the cliff, but to help guide them to the realization there was a better political system for them," says Mr. Powell.

Colin Powell was still a general in the army when he worked in the White House, and served the president as both a soldier and a diplomat. He told CBS news he learned valuable lessons from Ronald Reagan: how to be calm in a crisis, how to set a clear vision, and the importance of always looking at the bright side.

"If you are optimistic all the time, if you always believe that you can [do something], then others around begin to believe that. And the world looks to America as the nation that can, the nation that can put a man in space, the America that can believe in democracy, the America that over time solves its social problems. And America has always had that vision and that image to the rest of the world. Reagan was the personification of it," says Mr. Powell. "And when people looked at Reagan, they saw America."

Every business day at the White House for President Reagan began with a national security briefing. Colin Powell was responsible for those briefings, along with his deputy, John Negroponte, who has now been named ambassador to Iraq.

"I saw him every day for half an hour every workday as I accompanied Secretary Powell when he gave him his daily national security briefing," says Mr. Negroponte. "He invariably started off every meeting with the latest jokes he heard, using up at least five to seven minutes of our 30 minute time. He even kept them in a drawer."

But Ambassador Negroponte also remembers the serious side of Ronald Reagan.

"I think, sometimes people tend to underestimate how serious a man he was at heart, how well he did his homework," he says. "He was particularly interested in improving relations with the Soviet Union and I think that after that November 1986 meeting with [Former Soviet President Mikhail] Gorbachev, the whole attitude changed, from thinking of the Soviet Union as the evil empire to Gorbachev becoming his friend and all the things that followed from that."

His top aides remember him as a man of principle who knew when to compromise, and when to reach out to an old foe. They recall his upbeat attitude, even in times of deepest trouble.

Senator Elizabeth Dole was his secretary of transportation. She told CNN's Late Edition that she will never forget his grace even at the most trying moments. She recalled how, in the days after he was shot by a would-be assassin, he joked with his doctors.

"There were several surgeries, as you know, over a period of time there and the way he would bounce back and he was expressing humor for the doctors and he was waving from the Walter Reed [hospital] window," says Mrs. Dole. "He was always the enthusiastic, upbeat individual that inspired us all."

Ed Meese, a trusted legal adviser who became his attorney general, points to the difficult days when the Reagan White House was faced with the revelation that aides to the president sold arms to Iran and used the money to help the contra rebels in Nicaragua.

"It was something he knew nothing about while it was going on in terms of the unauthorized activity, but he was quick to make sure all the facts came out to the public," he says. "I think that in itself probably saved his presidency."

It was a low point for Ronald Reagan's presidency. But by the end of his second term, his job approval rating was one of the highest since modern public opinion polling began.

Colin Powell says there were many reasons why he was one of the most popular presidents of the 20th century: his optimism, his determination and his ability to lift up a nation whose spirit was still shaken from the Vietnam War, the Watergate scandals of the 1970's and the taking of American hostages in Iran.

Secretary Powell tells one final story. Not long after Ronald Reagan left office, Colin Powell, then retired from public service, visited his California home. Mr. Powell's driver was a soldier, who spoke of his admiration for the past president. When President Reagan opened the door to greet his guest, Colin Powell asked the young man, who was waiting in the car, to join them.

"The sergeant was stunned, couldn't say a word. He just did what sergeants do, came to attention and saluted President Reagan," says Mr. Powell. "President Reagan returned the salute. We went into the house, the sergeant went back to the car and President Reagan said to me 'Colin, is it still okay for me to salute?' And I said, 'Mr. Reagan don't you ever stop saluting. It means so much to us.'"

These former aides are all expected to attend the Memorial Service Friday at the National Cathedral. It will be an invitation only event. But there will also be opportunities for the American public to pay their respects, so they, like that young sergeant, can offer a salute to America's 40th president.