Costa Rica's membership in the newly formed United States of Central America, now free of Spanish rule, was short lived. The distance from Guatemala City to the Central Plateau of Costa Rica, where most of the population lived and still lives, was great. The local population had little allegiance to government in Guatemala City, in part because of the history of isolation during Colonial times. Costa Rica's disinterest in participating as a province in a greater Central American Government was one of the deciding factors in the break-up of the fledgling federation into independent states, which still exist today. However, all of the Central American Nations still celebrate September 15th as their independence day, which pertains to the independence of Central America from Spain.