It seems to be in our nature to draw lines that separate us from this or that. Rivers offer a convenient way for us to draw some of those lines, those boundaries, especially big rivers. In this episode, I tell a few stories about how we’ve used the Mississippi River to draw political lines, some of which didn’t quite go according to plan. (Ever wonder why Minnesota has that funny hat-shaped addition at the top?) I also look at how the Mississippi River marked a boundary between freedom and oppression for pre-Civil War African Americans in St. Louis and dig into the troubles we’ve made for ourselves by trying to define a hard boundary between land and water along a big river. We eventually, inevitably, built bridges—over a hundred of them!—to span the Mississippi and make crossing that boundary much easier. I take a look at what was involved in building a few of the earliest bridges, from the very first bridge to span the river at Minneapolis to its most enduring (the Eads Bridge at St. Louis). In the Mississippi Minute, I offer a tribute to a friend who passed away this year, David Lobbig, and wonder who will pick up his legacy of busting boundaries.