'Don't Touch Me,' Said Canada. 'I Won't!' Said The U.S.A. So They Moved 20 Feet Apart : Krulwich Wonders... Canada and the U.S.A. agreed to create a 20-foot-wide corridor between them that runs for 5,500 continuous miles. Cartographers drew the line straight, but engineers built it crooked. Take a look.

'Don't Touch Me,' Said Canada. 'I Won't!' Said The U.S.A. So They Moved 20 Feet Apart

The U.S. and Canada may be as lovey-dovey as two neighbors can get, but according to this charming video history by CGP Grey, both countries agreed to tuck themselves a little bit in, 10 feet back for America, 10 feet back for Canada, creating a corridor of open, surveillable, clear space between them.

This ribbon of emptiness is constantly monitored, regularly gardened (Baby Tree! Be gone!) and persists for 5,500 continuous miles — considered the longest deforested straight line in the world — protecting the U.S. and Canada from interlopers, or beavers without passports.

Except for one thing — it isn't straight.

The engineers who tried to follow the 49th parallel used primitive instruments, and, it appears, twine, and so the border got a wee bit zigzaggy, producing a number of problems, a few of which are delightfully described here ...

CGP Grey YouTube