Built for clarity rather than cinematic excitement, Harvest of Empire (2012), screening Sunday as part of the One World Film Festival, is a straightforward and important lesson in regional politics, from economic interconnections to covert operations.

Based on the book by Democracy Now cohost Juan González, the film presses past the distortions and prejudices that are shaping much of the immigration debate in the United States. It lays out a historical overview of U.S. policy in Latin America, illuminating its direct role in decades of northward migration by millions of people.

Talking-head interviews with a wide range of accomplished Latinos vary in their impact, but collectively they form a portrait that belies the image of a demonized other.

Directors Peter Getzels and Eduardo López and author González also present cogent statistics — including the fact that since at least 1820, Mexico has been the source of more legal immigrants to the United States than any other country.

Mexico is one of six nations whose ties to the States are explored; also profiled is Puerto Rico, in its still-thorny limbo between independence and statehood. The United States imposed citizenship on Puerto Ricans just in time for World War I conscription, the filmmakers point out, and they go on to trace the not unrelated pattern of recruiting expendable work forces from Mexico — valuable but not valued.

Though its snapshot approach is uneven, Harvest is a valuable resource: a good starting point for a fuller perspective on this nation of immigrants.

One World Film Festival: 'Harvest of Empire'

★★★☆☆

No MPAA rating. Harvest of Empire. 1:33.

When: 2 p.m. March 10

Where: Central Library Farish Theater, 140 E. Main St.

Admission: Free

Learn more: (859) 266-6073, Oneworldfilmfestival.org