The Mexican–American War, also known as the Mexican War and in Mexico the American intervention in Mexico, was an armed conflict between the United States of America and the United Mexican States from 1846 to 1848.
After obtaining independence in 1821, from the Kingdom of Spain Mexico became a republic in 1824. It was characterized by considerable instability, leaving it ill-prepared for international conflict only two decades later when war broke out in 1846. Native American raids in Mexico's sparsely settled north in the decades preceding the war prompted the Mexican government to sponsor migration from the U.S.A. on its northeast border to the Mexican province of Texas to create a buffer.
However, the newly-named "Texians" revolted against the Mexican government of President - dictator Antonio Lopez de Santa Ana, who had usurped the Mexican constitution of 1824, in the subsequent 1836 Texas Revolution, creating a republic not recognized by Mexico, which still claimed it as part of its national territory. In 1845, the Texan Republic agreed to an offer of annexation by the U.S. Congress, and became the 28th state in the Union on December 29 that year.
Mexico severed relations with the United States in March 1845, shortly after the U.S. annexation of Texas. In September U.S. President James K. Polk sent John Slidell on a secret mission to Mexico City to negotiate the disputed Texas border, settle U.S. claims against Mexico, and purchase New Mexico and California for up to 30 million dollars.
Mexican President José Joaquín Herrera, aware in advance of Slidell’s intention of dismembering the country, refused to receive him. When Polk learned of the snub, he ordered troops under
General Zachary Taylor to occupy the disputed area between the Nueces and the Rio Grande in January 1846.
Mexican forces attacked an American Army outpost in the occupied territory, killing 12 U.S. soldiers and capturing 52. These same Mexican troops later laid siege to an American fort along the Rio Grande. Polk cited this attack as a so-called invasion of U.S. territory, and requested that the Congress declare war.
Following its original plan for the war, the United States sent its army from the Rio Grande, under Taylor, to invade the heart of Mexico while a second force, under Colonel Stephen Kearny, was to occupy New Mexico and California. At that time, only about 75,000 Mexican citizens lived north of the Rio Grande. As a result, U.S. forces led by Colonel Stephen W. Kearny and Commodore Robert F. Stockton were able to conquer those lands with minimal resistance. Taylor likewise had little trouble advancing, and he captured Monterrey in September.
Meanwhile, the Pacific Squadron of the United States Navy conducted a blockade, and took control of several garrisons on the Pacific Ocean western coast farther south in lower Baja California Territory.
With the losses adding up, Mexico turned to old standby General Antonio López de Santa Anna, the charismatic strongman who had been living in exile in Cuba. Santa Anna convinced Polk that, if allowed to return to Mexico, he would end the war on terms
favorable to the United States. But when he arrived, he immediately double-crossed Polk by taking control of the Mexican army and leading it into battle. At the Battle of Buena Vista in February 1847, Santa Anna suffered heavy casualties and was forced to withdraw. Despite the loss, he assumed the Mexican presidency the following month.
Meanwhile, U.S. troops led by General Winfield Scott performed the first major amphibious landing in U.S. history in preparation for the Siege of Veracruz. A group of 12,000 volunteer and regular soldiers successfully offloaded supplies, weapons, and horses near the walled city using specially designed landing crafts. The Mexicans surrendered the city after 12 days under siege.
Scott then marched westward on April 2, 1847, toward Mexico City with 8,500 healthy troops, while Santa Anna set up a defensive position in a canyon around the main road about 80 kilometers north-west of Veracruz, near the hamlet of Cerro Gordo. In the battle fought on April 18, the Mexican army was routed.
In May, Scott pushed on to Puebla, the second largest city in Mexico. Because of the citizens' hostility to Santa Anna, the city capitulated without resistance on May 1. The major objective of American operations in central Mexico had been the capture of Mexico City. After routing the Mexicans at the Battle of Churubusco, Scott's army was only 8 kilometers away from its objective of Mexico City. After Churubusco, fighting halted for an armistice and peace negotiations, which broke down on September 6, 1847. With the subsequent battles of Molino del Rey and of Chapultepec, and the storming of the city gates, the capital was occupied. Scott became military governor of occupied Mexico City.
Guerilla attacks against U.S. supply lines continued, but for all intents and purposes the war had ended. Santa Anna resigned, and the United States waited for a new government capable of negotiations to form.
The 1848 Treaty of Guadalupe Hidalgo forced onto the remnant Mexican government, ended the war and specified its major consequence, the Mexican Cession of the northern territories of Alta California and Santa Fe de Nuevo México to the United States. The U.S. agreed to pay 15 million dollars compensation for the physical damage of the war. Mexico acknowledged the loss of their province, later Republic of Texas, and now State of Texas, and thereafter cited and acknowledged the Rio Grande as its future northern national border with the United States. Mexico had lost over one-third of its original territory from its 1821 independence.
The American Revolutionary War (1775–1783), also referred to as the American War of Independence and as the Revolutionary War in the United States, was an armed conflict between Great Britain and those thirteen of its North American colonies which after the onset of the war declared independence as the United States of America.
The close of the Seven Years' War in 1763 saw Great Britain triumphant in driving the Kingdom of France from North America, but heavily in debt. Britain's national
debt at the end of the war had doubled to £130,000,000 and the annual cost of the British civil and military establishment in America in 1764 was £350,000, five times the cost of 15 years earlier. Parliament passed the Stamp Act in March 1765, which imposed direct taxes on the colonies for the first time. This was met with strong condemnation among American spokesmen, who argued that their "Rights as Englishmen" meant that there could be "no taxation without representation"—that is direct taxes could not be imposed on them by Parliament because they lacked representation in Parliament.
This resistance became particularly widespread in the New England
Colonies, especially in the Province of Massachusetts Bay. Patriot protests escalated into boycotts. On December 16, 1773, Massachusetts members of the Patriot group Sons of Liberty destroyed a shipment of tea in Boston Harbor in an event that became known as the Boston Tea Party. The British government retaliated by closing the port of Boston and enacting punitive measures against Massachusetts, including the dissolution of its charter and the prohibition of its
traditional, democratic town meetings. Named the "Coercive Acts" by Parliament, these measures became known as the Intolerable Acts in America. The Massachusetts colonists responded with the Suffolk Resolves, establishing a shadow government that removed control of the province from the Crown outside of Boston. Twelve colonies formed a Continental Congress to coordinate their resistance, and established committees and conventions that effectively seized power.
British attempts to seize the munitions of Massachusetts colonists in April 1775 led to the first open combat between Crown forces and Massachusetts militia, the Battles of Lexington and Concord on April 19, 1775. Militia forces proceeded to besiege the British forces in Boston, forcing them to evacuate the city in March 1776. The
Continental Congress appointed George Washington to take command of the militia. Later he was appointed as commander-in-chief of the newly formed Continental Army, as well as coordinating state militia units. Concurrent to the Boston campaign, an American attempt to invade Quebec and raise rebellion against the British Crown there decisively failed. On July 2, 1776, the Continental Congress formally voted for independence, issuing its Declaration on July 4.
Sir William Howe began a British counterattack, focussing on recapturing New York City. Howe outmaneuvered and defeated
Washington, leaving American confidence at a low ebb. Washington captured a Hessian force at Trenton and drove the British out of New Jersey, restoring American confidence. In 1777 the British sent a new army under John Burgoyne to move south from Canada and to isolate the New England colonies. However, instead of assisting
Burgoyne, Howe took his army on a separate campaign against the revolutionary capital of Philadelphia. Burgoyne outran his supplies, was surrounded and surrendered at Saratoga in October 1777.
The British defeat in the Saratoga Campaign had drastic
consequences. France and Spain had covertly provided the colonists with weapons, ammunition, and other supplies since April 1776; in 1778 France formally entered the war, signing a military alliance that recognized the independence of the United States. Giving up on the North, the British decided to salvage their former colonies in the South. British forces under Lieutenant-
General Charles Cornwallis seized Georgia and South Carolina, capturing an American army at Charleston, South Carolina in May 1780. British strategy depended upon an uprising of large numbers
of armed Loyalists, but too few came forward. In 1779 Spain joined the war as an ally of France under the Pacte de Famille, intending to capture Gibraltar and British colonies in the Caribbean. Britain declared war on the Dutch Republic in December 1780.
In 1781, after the British and their allies had suffered two decisive defeats at King's Mountain in October 1780 and Cowpens in
January 1781, Cornwallis retreated to Virginia, intending on evacuation. A decisive French naval victory in September deprived the British of an escape route. A joint Franco-American army led by Count Rochambeau and Washington, laid siege to the British forces at Yorktown. With no sign of relief and the situation untenable, Cornwallis surrendered in October 1781, and some 8,000 soldiers were taken prisoner.
Whigs in Britain had long opposed the pro-war Tory majority in Parliament, but the defeat at Yorktown gave the Whigs the upper
hand. In early 1782 they voted to end all offensive operations in North America, but the British war against France and Spain continued, with the British decisively defeating both during the Great Siege of Gibraltar. In addition Britain inflicted several naval defeats upon the French, most decisively in the Battle of the Saintes in the Caribbean in April 1782. On September 3, 1783, the combatants signed the Treaty of Paris, ending the war. Britain agreed to recognize the sovereignty of the
United States over the territory bounded roughly by present-day Canada to the north, by Florida to the south, and by the Mississippi River to the west.
While French involvement proved decisive for the cause of American independence, France made only minor territorial gains, and incurred massive financial debts. Spain acquired Britain's Florida colonies and the island of Minorca, but failed in its primary aim of recovering Gibraltar. The Dutch lost on all counts, and had to cede Nagapattinam to the British.
The total loss of life throughout the war is largely unknown. As was
typical in the wars of the era, disease claimed far more lives than battle. At least 25,000 American Patriots died during active military service. Proportionate to the population of the colonies, the Revolutionary War was at least the second-deadliest conflict in American history, ranking ahead of World War II and behind only the Civil War.
