The United States of America is a large country to the south of Canada. Texas, in the United States was the home state of the International Student Space Simulation from which the OCESS was spun off. South Carolina based Lexington High School, also in the United States, used to run an exchange program with students from the United States until they discontinued their simulation programs.
The United States is a leading power in space exploration and have provided launch opportunities to Canadian Astronauts in the past.
Please see the Wikipedia article about the United States for more information.