"The American Revolution used funds collected from people living in the present states of Texas, New Mexico, Arizona and California--then a part of Mexico. An important percentage of financial support originated in New Spain, now called Mexico. Eventually, thousands of Spanish troops fought British troops throughout the Americas."
"One of the more important figures to assist the Colonies' struggle for independence was Bernardo de Gálvez. He helped the cause through diplomatic, financial and military exploits against Great Britain in the Mississippi River Valley, the Gulf Coast, including the Floridas, Louisiana and in in the Gulf of Mexico. from 1776, when he became govenor of Louisiana, until 1783 when the American Revolution ended, Gálvez's patience, audacity, appreciation of frontier people, diplomatic knowledge and military skill greatly contributed to the eventual British defeat."
See also State of Maryland declaration here.
See also this timeline, including thank-you letters to Galvez from prominent American forefathers Patrick Henry and Thomas Jefferson:
1777 Oct. -- Patrick Henry wrote two letters to General Galvez, thanking Spain for its help and requesting more supplies.
1778 Jan. -- Patrick Henry wrote another letter to General Galvez, thanking Spain for it's help and requesting more supplies.
1779 Nov. 8 -- Thomas Jefferson wrote to Gen. Galvez, expressing his thanks for Spain's assistance during the revolutionary cause.