Spain was not a bystander to the American Revolutionary War, although that fact is rarely mentioned in cursory historical surveys. Spain's motivation to help the American colonists was driven by a desire to regain the land it had lost to Britain and, with other European powers, make incremental gains against British possessions in other parts of the world. Although some dreamers in Spain perhaps envisioned its eventual possession of the entire New World, I have found no evidence that such an idea guided its assistance to the American colonists.

France and Spain were at that time both under Bourbon kings, Louis XVI and Carlos III, respectively, whose American possessions had been significantly reduced by the 1763 Treaty of Paris that ended the Seven Years' (the French and Indian) War. At the beginning of the American War of Independence, American commissioners were sent to Europe by the Continental Congress to seek support for their cause. John Jay, American representative in Spain, found success. Americans promised both France and Spain the restoration of much of the land they had lost to the British in America. In April 1779, Spain committed to helping the Americans.

This help did not consist of Spanish troops to fight alongside Americans, but it was extensive nevertheless. The Spanish and French kings provided large loans and outright contributions of money to the Americans. Spain laundered this money, as we would say today, through a fictitious private trading company, Roderique Hortalez and Company, operating out of the Lesser Antilles, which sent both money and war material directly to the Americans. The money helped support the Americans' new currency, the Continental, and also made it possible for the Americans to bring in foreign military officers, such as Augustus von Steuben, Casimir Pulaski, and Thaddeus Kosciuszko, to fight for them.

Spain began a military campaign of its own against the British in Florida and Louisiana. From 1779 through 1782, the Spanish Governor of Louisiana, Don Bernardo de Gàlvez, conducted a series of military actions against the British to retake forts that Spain had earlier lost to the British, succeeding in the Mississippi River Valley, and at Baton Rouge, Natchez, Mobile, and Pensacola. In 1782, Spain also succeeded in wresting back the Bahamas from the British.

A very substantial form of Spain's support for the Americans involved a strategy of joining Britain's other European competitors in tying up British naval resources by engaging them elsewhere than in Britain's American colonies. Spain did this, for example, against Gibraltar and Minorca, and together with France sent a fleet into the English Channel to menace the British coast and tie up more British ships. Most of the European maritime powers, including Spain, united against Britain's effort to interrupt their trade with America. With both France and Spain (and Holland) indirectly in the fray, Britain's navy was outmatched and could not effectively concentrate its military force in America. Spanish ships joined with French ships in the naval blockade of the British army at Yorktown in 1781, preventing General Cornwallis's resupply by the British navy, resulting in his surrender.

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After Spain's public acknowledgment in June 1779 that it would join with France to wage war on Britain, the Governor General of Spanish Louisiana, Bernardo de Gálvez, began his successful military campaign against British forces in Florida, Louisiana, and in the Mississippi River Valley.

John Jay's mission to Spain, which began in September of that year resulted in no additional direct aid to the American colonies, although Spain funneled some money to them indirectly, which helped the Colonies stabilize its currency. But Spain had had reasons of its own to harass Britain militarily and it had begun to do just that, conscious that Britain's world-wide military power would be occupied to some extent by the revolt of its colonies in America.

The Catholic monarchy of Spain, however, had little sympathy with the British colonies' budding republican ideals. The U.S. State Department's website, describing Jay's mission to Madrid, says that Carlos III's minister, with whom Jay dealt, "worried about American claims to lands west of the Appalachians and navigation rights on the Mississippi River and feared that the flames of the American revolution might spread to Spanish colonies in the Americas."

Nevertheless, his worry did not hinder Spain's pursuit of its own interests in America against the British and this certainly had the indirect but substantial effect of supporting the American colonists.

Anglo (meaning non-Hispanic white) migration to Texas began in earnest after Mexico secured its independence from Spain in 1821. In the new republic, Texas was just one part of the state of Coahuila-Texas, a region in Mexico's northern borderlands in which Native communities were powerful. Mexican families lived throughout the northern portion of Coahuila-Texas—the wealthiest of whom were known as Tejanos—and to the Comanche and Lipan Apache they were unwelcome. Viewed from the perspective of the region's Native communities, both Tejano and Anglo settlers were undocumented immigrants.

Many of the first Anglo immigrants to Texas were squatters, individuals who had no Mexican legal claim to their land. By 1824, however, both Mexican and Tejano officials welcomed Anglo settlers, although for very different reasons. The Mexican government wanted assistance securing the country's northern border against raids by the Comanche and other Native groups; the Tejanos wanted help in raising Texas to the level of Mexican statehood, independent of Coahuila, so that they might govern themselves more effectively. Anglo settlers wanted land, and they were initially willing to accept multiple conditions on their immigration in order to get it. In 1825, Mexico passed the Coahuila-Texas colonization law, which offered men at the head of households 177 acres of farming land, grazing rights, and tax breaks in order to settle the region. In return, settlers had to agree to become Mexican citizens, to practice Catholicism, and to uphold all Mexican laws, including those that prohibited slavery.

The vision of colonization held by Mexican officials was soon upended. By the mid 1820s there were more Anglo settlers in Texas than Tejanos, and Anglo families refused to settle where Mexican officials preferred them to go. Instead, they clustered around the state's eastern borders, which made the Mexican government nervous—it appeared that the United States' borders were encroaching into Mexican territory by default.

The Mexican government had good reason to worry. Not only were Anglos more culturally and politically allied with the United States than Mexico—especially on the subject of slavery—but Tejanos initially allied themselves with leading American settlers like Stephen Austin, believing this would position them to gain sovereignty. Mexico's worries were further compounded by the United States offering $1 million for Texas in 1827, and $5 million in 1829. On both occasions, Mexico declined.

By 1832, more than 6,000 Anglo settlers, who owned more than 1,000 slaves, lived in Texas. This compared with 3,000 Tejanos. Some relationships between Tejano families and Anglos became strained when settlers refused to recognize Tejano land rights and forced families from their farms. Many wealthy Tejanos still felt their interests were best served by alliance with Anglo leaders, however, and it was their cooperation that helped make Texan independence possible in 1835. Tejanos fought alongside Anglos in the ensuing war with Mexico, but in the face of a wave of new immigration after Texas declared itself independent of any larger nation, their political and cultural influence in the region declined. Most new Anglo settlers believed that their culture was superior to that of Tejanos and Mexicans alike, and racial prejudice was rife.

The Mexican government never recognized Texas as an independent state. When the United States annexed Texas in 1845 Mexico once again went to war. After three years, the peace Treaty of Guadalupe Hildalgo saw the transfer of millions of acres of Mexican territory to the United States government—modern-day Texas, Arizona, New Mexico, and California, as well as portions of states further north. Anglo settlement, which had once seemed a sound strategic defense against borderland warfare with Indian people, proved the thin edge of a wedge that saw Mexico lose more than half of its territory to the United States.

The Comanche and Lipan Apache continued to defend their territory against immigrants for many more years.