When Alan Alda walked through the halls of the U.S. Senate in the movie "The Seduction of Joe Tynan," he was actually walking through the halls of the State House in Annapolis.

Al Pacino's fiery speech as an incorruptible attorney in the film ". . . And Justice For All," was delivered in the Criminal Courts Building in downtown Baltimore.

And when a replica of the Mayflower weighed anchor in the television movie, "The Voyage of the Mayflower," the ship was sailing on the Chesapeake Bay.

The man who helped generate all of this cinematic activity is 65-year-old Jack Smith who, as head of the fledging Office of Motion Picture and Television Development, is bringing Hollywood to Maryland.

His office was opened as part of the Department of Economic and Community Development two years ago and thus far, the Hollywood traffic has been steady. Two major movies are being filmed in the state this spring.

"Diner," a comedy-drama about the coming of age of five childhood friends at the close of the 1950s, is now being filmed in Baltimore. It was written and is being directed by Baltimorean Barry Levinson, who coauthored the script for ". . . And Justice for All" and wrote the screenplay for "Inside Movies." The "diner" has been set up on a vacant lot in the Fells Point area amidst vintage cars and billboards from the 1950s.

"Revelations," starring Sally Fields and directed by Jack Clayton ("The Great Gatsby") begins 12 weeks of shooting in the Westminster-New Windsor areas of Carroll County in May. The events in the film, which was adapted from the novel by Bethesda author Phyllis Naylor, are supposed to take place near La Plata in Charles County, but moviemakers felt the Carroll County scenery was more suitable.

While moviemakers bring a certain glamor and excitement with them, they also bring some things more important: jobs and money. The crew of a low-budget film, Smith said, will spend between $25,000 and $30,000 a week in restaurants, hotels, hardware stores, cleaners and other local businesses, while a high-budget film will add between $50,000 and $75,000 a week to the local economy.

Some crews making commercials spend between $500,000 and $1 million during a shooting, Smith said.

During its 16-week stay in Baltimore, the crew of ". . . And Justice For All" spent about $1.5 million. Smith, whose tiny agency had a budget of $18,500 last year, considered that a fair return on the state's investment.

Smith, a native of Washington, D.C., worked in the advertising departments of the Washington Star and the Daily News before going into television. In the early 1950s, Smith was involved in the production of live television shows such as "Philco Playhouse," "Playhouse 90" and "Dave Garroway at Large."

He joined the Maryland Office of Economic and Community Development in 1977 as communications supervisor, during which time he produced, wrote and directed two documentary films for the state and was executive producer of a third.

"It was interesting enough, but not what I wanted to do," Smith said. So he began to work on the idea of bringing motion-picture producers to Maryland. The initial reaction from state officials was less than enthusiastic.

"The usual reaction was: 'If they want to come to Maryland, they'll come. Just wait,'" he said. But Smith persisted, and the Office of Motion Picture and Television Development was born and he was named to the $23,200-a-year director's post.

"Production for TV and movies are quite similar," Smith said. "I know what people are looking for."

Maryland's major asset in attracting filmmakers, said Smith, is that the state has landscapes that can duplicate any geographic area of the country.

An airfield outside Annapolis was supposed to be Louisians in "Joe Tynan" and a forthcoming commercial will transform the Eastern Shore into the plains of Iowa.

"We have everything," Smith declared.

Smith also makes good use of Maryland's many historic places, which can be used in films dealing with early periods of U.S. history. A brochure Smith distributes lauds the state's historic sites, including the U.S. Naval Academy at Annapolis -- ". . . 18th century air unmatched in picturesque authenticity" -- and Fort McHenry.

It concludes by urging producers to shoot in Maryland: "You will find that Maryland offers you the freedom to interpret your script exactly as you want -- there is little or no need to improvise a location."

The process of luring a producer to Maryland is a lengthy one. Smith lays the groundwork with advertisements in trade journals and a slick, full-color brochure that is sent to nearly producer and includes plaudits from directors who have worked in Maryland.

Norman Jewison, producer and director of ". . . And Justice For All," is quoted as saying, "I would have no hesitation in returning and most certainly recommend the city (Baltimore), the state and the people to my fellow filmmakers."

Recruiting filmmakers is a highly competitive venture, Smith said. "There are 48 states that have some kind of film office, and 17 major cities," he said.

Smith favors a style of salesmanship that is low-key but, he believes, effective. He sometimes visits producers on the West Coast to pitch the state. "When I go, I represent Maryland," he said. "I tell them if they want to do it. A lot of noise won't help."

Smith gets help from a network of people in every county -- usually representatives from the country economic development authority who are familiar with every part of the local terrain.

Once a suitable site has been found, a videotape is made, complete with narration, and sent to the producer. The tape covers every conceivable detail, including the number of electrical outlets at the site and the location of the nearest hotel.

"Suppose you find the house you want," Smith said. "Can they shoot inside of it? Is there room to set up a camera?"

Recently, Smith wanted to find a rural location for a Texaco gasohol commercial. The commercial will feature Texaco spokesman Bob Hope riding around the countryside in a car shaped like an ear of corn. Smith placed calls to the directors of economic development for Montgomery and Prince George's counties, and within four hours they had come up with several potential locations.

Once the final site selection is made, beginning of a picture, when the production manager comes to town, we turn over our duties to local people that are in that business -- people that can find caterers, car rentals, whatever."

During the past several months, Smith has received assistance from the state Motion Picture and Television Development Advisory Council, a 13-member group headed by Frederick Breitenfeld, director of the Maryland Center for Public Broadcasting.

"I believe that, as important as location is, the assurance that there will be cooperation from police and citizens, help for the housing of the crew and staff," Breitenfeld said.

Breitenfeld also wants to convince producers that they don't have to go to New York to find the kind of high-caliber talent they need on the set, whether it be a cinematographer or a character actor.

"I think there is much talent in this area than we are given credit for," he said.