The decisions were made in engineering offices, documented in route studies, and implemented over roughly a decade. Their effects have outlasted every institution involved in making them.

In St. Paul, the construction of Interstate 94 through the Rondo neighborhood displaced approximately one in eight of the city's Black residents and destroyed a commercial district, a set of churches, and the accumulated property wealth of hundreds of families.

Alternative routings were available and were rejected. A northern route along an existing rail corridor was studied, cost less to acquire, and displaced fewer people. It was opposed by commercial interests along that corridor, who were better organized and better connected than the residents of Rondo.

The argument advanced at the time was technical: alignment, grade, connection to downtown. The record of who was consulted and who was not is unambiguous enough that the technical framing has not survived historical review.

Minneapolis has its own version, less concentrated and therefore less remembered. Interstate 35W was routed through the near north and south sides, and Olson Memorial Highway cut through the heart of a Black neighborhood on the north side that had also housed the city's largest Jewish community.

The mechanism was the same. Federal highway funds covered ninety percent of construction costs, which made routing decisions nearly free to local governments. Land was cheapest where property values had been suppressed by decades of racially restrictive covenants and redlining — a suppression that was itself the product of policy.

The city had been comprehensively covenanted. A mapping project at the University of Minnesota has documented thousands of Minneapolis property deeds containing clauses barring sale or occupancy by non-white residents, concentrated in the neighborhoods that became and remain the city's wealthiest.

Covenants were made unenforceable in 1948 and were not removed from deeds. Minnesota later created a legal process for homeowners to discharge them, and thousands have.

The highways cannot be discharged. They are physical, they carry enormous traffic volumes, and proposals to cap, reroute or remove segments face costs in the billions.

Both cities have begun formal processes examining the possibility. St. Paul's Rondo land bridge proposal — a deck over the freeway rebuilding the neighborhood's severed grid — has advanced further than most observers expected.

Descendants of displaced families have been clear that reconstruction is not restoration. "You cannot rebuild a neighborhood," one told a public meeting. "You can stop pretending it left on its own."