You might have been in a suburban multiplex watching "Star Wars" at the time — back when it was just "Star Wars."

But if you were in St. Paul in 1978, you were witness to a turning point in downtown, even if you didn't know it at the time. It was driven in part by a brief public transportation craze known as the "People Mover," proposed by the federal Urban Mass Transit Administration in 1975: think of an elevated airport-tram-like system that was going to circulate through downtown.

An image of a people mover proposed for, and never built in, Houston. It is similar to the one that was proposed to be built in 1978 in St. Paul. Courtesy of Christopher Andrews

"Yes, 1978 ... The day downtown died," said architecture historian and critic Larry Millett — not entirely in jest.

The year is the subject of a new photography exhibit opening Thursday at the Landmark Center, in conjunction with Historic St. Paul and marking National Preservation Month. The exhibit is a series of 30 images from the late summer and fall of 1978 by Minneapolis photographer Jerry Mathiason — just a sample of about 800 photos he shot as potential illustrations of St. Paul for a proposal to build, and the state to fund, the controversial People Mover.

Jerry Mathiason stands on St. Peter Street, about where he took a photo of a bus stop in 1978, as St. Paul began a major downtown redevelopment effort. Tim Nelson | MPR News

"There was a lot of push toward major developments in downtown St. Paul," Mathiason says of his work. "I have a lot of scenes with cranes in the background."

Bus riders wait to board an MTC bus on St. Peter Street, behind the Palace Theater, in this photo taken by Jerry Mathiason in 1978. Jerry Mathiason

The photos include the Town Square development, called the "city within a city" built across Seventh street, which severed the historic commercial and retail spine of downtown. The development was to contain a shopping mall, a third-floor public park, and a proposed terminal for the People Mover.

Voters nixed the People Mover in 1980, leaving odd artifacts still visible: a diagonal slash left between the UBS Plaza and Bremer Tower office buildings downtown was to have accommodated the People Mover guideway, according to transit historian Aaron Isaacs.

A view of the historic retail along West Seventh Street, near what is now the Xcel Energy Center, taken by photographer Jerry Mathiason in 1978. Jerry Mathiason

Mathiason's photos show downtown just before the change. There are the last remnants of post-World War II retail — a camera shop on Wabasha, an appliance shop and an auto parts store on West Seventh Street. In one shot, a trio of elementary school-aged girls plays on the corner of Kellogg and Seventh, a testament to the easy access to downtown from nearby residential neighborhoods.

There are runners jogging down the old Wabasha Street bridge, aging department stores and vacant blocks cleared of 19th century buildings. Some of the photos show the city's then-incomplete skyway system, before foot traffic moved mainly indoors and up to the second level of downtown buildings.

"There was this gradual extinction of small buildings, which supported a lot of street level retail, and then the retail itself," said Millett.

Three girls play on West Seventh Street, near the St. Paul Civic Center. Jerry Mathiason

Mathiason recognized the change but didn't entirely recognize the moment.

"I was just freelancing it. It was a lot of fun," Mathiason says. "I was just a year out of the University of Minnesota. In the 60s the big arts movement was street photography, and I did a lot of that. This allowed me to go back to this whole mode of what's going on and people interacting on the streets."

Some of those very streets are gone: Seventh Street was vacated for blocks, turned into private commercial space. Traffic was diverted onto Eighth Street, formerly a service corridor for the downtown core.

"In a sense, St. Paul is still struggling with those decisions. You've got the Rice Park area which is very nice, and they've got Lowertown, which is doing well, and then they've got this big blank middle which is just unpleasant for the most part," Millett says. "It was not St. Paul's finest hour, in terms of how this was all planned out."

A wooden boxcar stands on a siding on St. Paul's riverfront, before the Science Museum and District Energy plants were built. Jerry Mathiason

The photography exhibit has an opening reception in Landmark Center at 5 p.m. Thursday and runs through May 26.

Admission is free and a panel discussion of the era, "We Were There: St. Paul, 1978," is scheduled for next Tuesday, from 12-1 p.m., in Courtroom 326, featuring Mathiason, then-mayor George Latimer and Macalester urban geography professor, David Lanegran.