Oil, natural gas, Ford Pickups and auto parts, potash, aircraft & parts, gold & lumber are the biggest imports in order according to a search I just did on the Google.
Most of the oil goes to the west coast refineries. The Keystone pipeline was all about reducing the cost of bringing Albert heavy crude oil to the refineries in LA & TX that have excess capacity to refine this type of crude oil. I personally would rather buy Canadian oil than Venezuela or Saudi Arabia, etc. Same with natural gas.
I think most Ford F series trucks are made in Windsor, ONT.
I drive a Tacoma made in San Antonio.
Apparently, most of the potassium chloride(potash) we use in the country for fertilizer comes from Saskatchewan.
Bombardier makes a lot of commuter airplanes. Small jets and turboprops. I think they also make skidoos, atvs, etc.
We import a lot of Canadian softwood lumber. As a lumber broker I can attest to that.
I said “need”. None of those things are unavailable in the US. Liberal politics has driven our buying from Canada. Now that we have a man in the whitehouse, we can get back to America First! America Wins! and not some lame-assed country like Canada.