George Washington steps out of his horse-drawn carriage. Blue-coated soldiers, rifles at their sides, applaud him. He is about to deliver his farewell address to his troops, and a small crowd has turned out to show its appreciation. The horses stand quietly in the dusty, dirt road. Washington walks solemnly by, turns on his heel at the doorway and pauses to study the group. It is a moving moment for the leader and his countrymen. But wait . . . is that a little grin on his face?

And why is it so hot on December 4, 1783?

And what about those parking meters standing beside the horses?

For the past month, David Gerber/MGM has been filming an eight-hour mini-epic in Alexandria called "George Washington." The mini-series, scheduled to be shown this spring, will chronicle the first president's life from ages 11 to 50, ending up at the close of the Revolutionary War.

George Washington is actually actor Barry Bostwick. (His stand-in, 24-year-old Randy Anderson, is the son of columnist Jack Anderson.) Patty Duke Astin plays Martha Washington and Jaclyn Smith plays Sally Fairfax, for whom Washington carries a hidden torch. Sally Fairfax is the wife of Washington's close friend, George William Fairfax (actor David Dukes).

Then there are other stars who will come to town for a few weeks here and there to play their parts. Hal Holbrook as John Adams, Trevor Howard as Lord Fairfax, the British landowner with territories in Virginia. In a few weeks, Jose Ferrer will appear as Robert Dinwiddie, lieutenant governor of Virginia. James Mason has come and gone as Maj. Gen. Edward Braddock, the commander of British forces in the French and Indian War. So has Lloyd Bridges, who plays Caleb Quinn, a trapper-guide who accompanies Washington on his first trips into the wilderness. Bridges was loved by the cast and crew and ate with them in the lunch hall near the shootings. (Most of the stars eat in their trailers.)

Consider the absurdity of the scene: A man in a wig and heavy coat in 90-degree weather turning to give his troops a sober smile. Under the circumstances, Barry Bostwick looks more like he's playing Chevy Chase playing George Washington.

Clumps of pedestrians line North Royal Street in Alexandria, not so much to get a glimpse of George Washington as to peek at Hollywood. A chance to watch it at work, maybe even be part of it--like the extras who had their heads shaved to play Indians or the school principal who took the day off to play a townsman.

Surprisingly, an open shoot on an Alexandria street as Washington bids his officers farewell is a friendly, laid-back affair from the perspective of security. Fake post-Revolutionary townspeople in tailored coats and tricornered hats stroll down the part of North Royal closed to traffic, passing real townspeople wearing shorts and mini-skirts, toting children who wander by to watch the filming. No one seems to be getting in anyone's way.

But two hours later, inside Gadsby's Tavern, where they are filming a ball in 1766 Williamsburg, it is quite another scene altogether. The ballroom is packed: actors, extras, the Old Dominion Dancers, a local group specializing in early American country dancing, musicians, the director, the first assistant director and his assistants, the cameramen, the wardrobe mistress, hairdressers, the publicist, the advertising photographer, the Old Dominion Dancers' photographer all crowd this room amid cameras, ladders (two of them), and a tangle of wire from the lights.

Gadsby's Tavern is a historic building, and Jean Taylor Federico, the director of Historic Alexandria, is present, watching intently, worrying about the weight on the floor, and trying to figure out whom she can ask to leave. The Alexandria fire marshal is also there just in case.

There is a brief rehearsal in the front of the ballroom, while director Buzz Kulik tiptoes to the back of the room, finger to lips in a request for silence.

For this scene, Barry Bostwick has been "youthened" (a favorite word around the set) about 17 years. The actors will twirl around each other in a dance called "Hunt the Squirrel," which Barbara Harding, of the Old Dominion Dancers has taught them. Everyone seems in good spirits, grinning and joking with each other while they rehearse. They are all in full regalia. Patty Duke Astin wears a sweeping, low-cut purple gown, and Jaclyn Smith wears pink and clutches a fan. Her hairdresser carries Smith's gold Rolex watch with diamonds circling the dial, pinned to her shirt.

"Do we have all the dancers here now?" calls Buzz Kulik. "Okay, let's make this movie now."

And to the background people, the first assistant director instructs: "Pantomime, have fun with each other, but DON'T TALK."

"I would like to convey a warmth and earthiness within the confines of the period," says Patty Duke Astin about Martha Washington. Unfortunately, she's found little on the first first lady.

"There isn't a lot to get," Astin says. "So every tidbit is gold. She relished her own privacy. She destroyed her own letters from George."

In her non-Martha hours, Astin acts like a tourist. She and Barry Bostwick and his cousin went down to the Capitol grounds for a National Symphony Orchestra concert last weekend. And Astin set out to visit her relatives in Bethesda--got lost and ended up in Laurel.

"You miss the personal side of history a lot," says Jaclyn Smith, sitting in her trailor. "This script is loaded with emotion and sentiment. I love sentiment." She is between costumes, wearing a white shirt and faded jeans. Her 17-month-old son, Gaston, clambers around her and his nanny, Vikki Morris, pulling at the draperies in the trailor.

She is happy with this project, she says. "I love mini-series--they're one of the greatest breakthroughs in television."

She describes her character, Sally Fairfax, as a "sort of Scarlett O'Hara character--she's flirtatious and bubbly and vivacious. She's sort of the love of his young life--but an innocent love."

One trailer away, the young George is speculating on his character. What do you play after George Washington? "You probably play someone very normal--with a lot of neuroses," Bostwick says.

The whole series will be "one of the most expensive films per hour in terms of mini-series," says Richard Fielder, the producer and writer. "You're talking about $2 million an hour." Or $16 million total. "It's going to run more when you add the casting," he says.

The film company will spend $3 million to $4 million during its stay in Virginia, according to Christopher Seiter, the executive production supervisor.

"My sons are in Even's Platoon," says writer-producer Richard Fielder of 19-year-old John and 22-year-old Richard Jr., referring to a soldier troop in Washington's army. "One collapsed of heat stroke at the Battle of Monmouth." His 26-year-old daughter, Elizabeth, is a production assistant with the crew.

Even Fielder Sr. has a part. "One day I walked on the set and Buzz Kulik said, 'You've got to help me.' " Kulik needed an actor to play the French ambassador--also a military man--who comes out of his tent in a French encampment during the French and Indian War and gets shot by British and American militia.

"It's so desperately important that this series succeed," says Fielder of the movie, which is based on the four-volume biography by James Thomas Flexner. "It's the first time in television that we've dealt with history that wasn't fictionalized upfront. I think it's a revolutionary moment--if you'll pardon the pun."