Spain. Later Mexico was occupied by France but won that war too.
The revolutionaries (who fought against Mexican federal troops).
Spain
If by often you mean the longest, yes it is. It kept Mexico as a colony from 1521 until 1821 when Mexico fought an won its independence war.
Mexico fought a War for Independence from Spain from 1810 to 1821.
Texas was part of Mexico at the time. Fifteen years after Mexico got its independence from SpainTexas fought Mexico for it's independence, and won.
It has remained independent from Spain since 1810.
Mexico won the 11 year war and won its independence from Spain. Mexico was to have the missions shut down. That was the end of the missions system.
Miguel Hidalgo was the first man to fight for Mexico's independence. He fought for 2 years then was captured and decapitated. The second man to fight was Jose. He fought for 4 years and then died. The last man to fight and win Mexico's independence was Augustus de Iturbide. He originally was on the side of Spain who was fighting against Mexico at the time but suddnely thought "Hey, if I win these guys independence I can be their emporer."
Mexico after 11 years.
Texas which they won (gained their independence from Mexico) and then asked the US to annex them and they were annexed in the Union as a slave state.
The Scots (as a whole nation) never fought a war of independence.