This Donald Trump guy has made a lot of stink about this big, beautiful border wall he’s going to build, but there’s one small detail most of his supporters can’t seem to appreciate: it’s already been built. And the American people paid for it. Sure, it doesn’t cover the entirety of the 1,989 miles that run between the United States and Mexico, but Republicans discovered long ago that it’s functionally impossible to cover that entire stretch with giant, interlocking concrete and steel slats. The reasons are varied, but they involve things like private property, mountains, rivers, and a university library.

Those of us without historical amnesia might even remember how this all went down back in 2006, when President George W. Bush signed the Secure Fence Act to “help the protect the American people,” and to “keep our borders more secure.” Sound familiar? But the effects of Bush’s 800-mile-long fortification where much more devastating than anyone could have predicted at the time.

The 2009 documentary The 800 Mile Wall, directed by journalist John Carlos Frey, takes a close look at this process from both a political and humanitarian perspective. Employing archival footage and original interviews, The 800 Mile Wall shows us the impact this decision had on the thousands of people who risk their lives to cross the border each year.

As we see in the trailer, increased border security merely forced desperate migrants to take ever-more perilous journeys through unforgiving terrain, leading to an unending cycle of tragedy and death. Interviews with bereaved family members and observational footage are intercut with images of overstocked morgues and memorials for those who have passed. In all, The 800 Mile Wall a powerful reminder of the human toll of border enforcement, and a saddening document of a time – not so long ago – when even the harshest immigration rhetoric was tempered by compassion and humanity.