GREENFIELD — Residents can learn about the beginnings of the Clamshell Alliance as a nonviolent movement that sought to stop the construction of the Seabrook Station Nuclear Power Plant through two upcoming screenings of “Acres of Clams.”

“Acres of Clams,” a new release from Eric Wolfe of San Francisco who was involved in the Clamshell Alliance’s anti-nuclear campaigns of the 1970s to 1990s, will be screened at the Garden Cinemas in Greenfield on Tuesday, April 22, at 6:30 p.m. with $5 admission to the theater, though donations to the Clamshell Alliance will also be accepted. It will also be shown on Saturday, May 3, at 2:30 p.m. at Belchertown’s Clapp Memorial Library.

‘“Acres of Clams’ is a film for these times we’re in. It shows a path forward, in a disciplined and joyous way,” Sharon Tracy of the Clamshell Alliance said in a statement. “We hope Earth Day participants and all who care about the environment will come and enjoy this film.”

Using archival footage and interviews with Clamshell Alliance organizers, the film tells the story of how local opposition to nuclear power grew into a national movement against the construction of nuclear power plants. At that time, President Richard Nixon had announced plans for more than 1,000 nuclear plants. After the Seabrook protests, which spawned others across the country, the total number of nuclear power plants built in the U.S. was stopped at 94.

“This film shows the formation of a grassroots movement from the ground up,” Susanae Glovacki of the Clamshell Alliance said in a statement. “It shows how strategic nonviolence welcomes and builds creativity and community among organizers, and how it can engage the public in unique and powerful ways.”