I am Canadian and was able to immigrate based on employment as a flight instructor.
I went to UND. When I graduated I decided I wanted to stay in the US. UND wouldn't sponsor me, so I got a job at an FBO with the understanding that I wanted them to sponsor me.
I got to work for them with an H1B1 visa. That was probably the hardest part of the whole process. I had to prove that the job required a 4-year degree. I made the argument and immigration bought it. Then I went through the "labor certification" process where I proved that no American was interested in the job. After that it was all paper work and waiting. Not really hard, but not many employers want to take the risk of it not working out. I got lucky.