Every time Gregory Peck moved in front of a portrait or a photograph of Abraham Lincoln last night, the cameras flashed. Peck looked more than pleased, because Lincoln is a personal hero.

"Ah, that's the one that caught it," said Peck, standing at the National Portrait Gallery in front of the last photograph made of Lincoln. "I think of him as a real man, a flesh-and-blood person. I don't think of him as mythology. I long to meet him, long to have a conversation with him."

Many of the people standing around Peck thought the actor had given them some proximity to Lincoln and other heroes. In a forthcoming mini-series on CBS, "The Blue and the Gray," Peck portrays Lincoln. "But when I think of Douglas MacArthur now, I think of Gregory Peck," Richard Wiley, former Federal Communications Commission chairman, told the actor. Now Peck looked less than pleased. "In that film we wasted 1 1/2 hours until the Truman-MacArthur conflict," he said.

In the theater where Lincoln was shot (Ford's), and the hall where Walt Whitman and Clara Barton tended the Civil War wounded (the National Portrait Gallery), a Washington audience previewed and then celebrated the eight-hour mini-series. Justice Sandra Day O'Connor, who had walked the two blocks between the buildings, gave the historic pageantry her endorsement. "Especially those scenes filmed in Virginia, they looked like a painting," said O'Connor.

Though he didn't see the preview, Defense Secretary Caspar Weinberger stopped by to speak to his wife, Jane, his son, and Peck. Caspar Weinberger Jr., a special projects director for USIA, had been particulary impressed by a scene in which a Union and a Confederate deserter meet. "They really communicated with each other," said Weinberger. "They got to the human part."

Federal Communications Commissioner James Quello said the same scene evoked a personal memory. "Was that the way the Civil War was?" interrupted Wiley. Laughing, Quello explained, "During World War II, I was at El Guettar and an Italian ran through our lines and said, 'Don't shoot, I'm from Brooklyn.' "

Thomas Wyman, the president and chief executive officer of CBS Inc., predicted that the drama, which will be shown the week of Nov. 14, would become part of the redefining of America. "It's going to be tied in with the schools and with the current discussion of what is this country. The Civil War was a time the country did identify itself." Last night's audience also included Justice Harry Blackmun; Susan Clough, former secretary to Jimmy Carter; newsman Eric Sevareid; and Alan Fern, director of the Portrait Gallery.

Last night was the third time Stacy Keach, who plays a scout and bodyguard to Lincoln, had seen the film. At this preview, he provided a running commentary on the story and was particulary moved by one of his own scenes, Lincoln's death. "It was a jolt. I had thought about being in the theater where he was shot, but it wasn't a reality until that moment," said Keach. Another star, Diane Baker, had felt similar chills. "When Lincoln died, and they said it was 7:22, my friend turned to me and said it was 7:20," said Baker. John Hammond, who plays the other lead character, an artist and correspondent, was also at the reception.

When director Andrew McLaglen first saw the script, which is based on the work of the late prize-winning historian Bruce Catton, he thought immediately of Peck. "He had told me once before he had wanted to make a definitive Civil War picture. When he read the script, he said he hated anyone else doing Lincoln but him." Meanwhile, last night Peck was having a hard time getting to talk with his daughter, Cecilia, who is a reader and consultant for ABC Motion Pictures.

Finally, they stole away from the Civil War-era marching music to look at some Mathew Brady photos of Lincoln. "Look at those burning eyes," Peck said.