Why was great Britain interested in restraining the influence of European nations in the America's?

Great Britain was interested in restraining the influence of European nations in the Americas because they were afraid that their profitable trade with the newly independent countries would be hurt if Spain regained control of its former colonies.

Explanation:

Great Britain was afraid that their profitable trade what they have started with their newly independent countries would be hurt if Spain regained control on its former colonies. In 1812 war Great Britain defeated Spain and some other countries and captured their colonies.

The war was ended when Great Britain and United States of America both signed the Treaty of Ghent. Main thing of the treaty was that no country will take authority on other country's territory. The borders will be same as on or before the war.