Timeline of the Mexican-American War

Timeline of the Mexican-American War The Mexican-American War (1846–1848) was a brutal conflict between neighbors largely sparked by the US annexation of Texas and their desire to take western lands such as California away from Mexico. The war lasted about two years in total and resulted in a victory for the Americans, who benefited greatly from the generous terms of the peace treaty following the war. Here are some of the more important dates of this conflict. 1821 Mexico gains independence from Spain and difficult and chaotic years follow. 1835 Settlers in Texas revolt and fight for independence from Mexico. October 2: Hostilities between Texas and Mexico commence with the Battle of Gonzales. October 28: The Battle of Concepcion takes place in San Antonio. 1836 March 6: The Mexican army overruns the defenders at the Battle of the Alamo, which becomes a rallying cry for Texas independence. March 27: Texan prisoners are slaughtered at the Goliad Massacre. April 21: Texas gains independence from Mexico at the Battle of San Jacinto. 1844 On September 12, Antonio Là ³pez de Santa Anna  is deposed as President of Mexico. He goes into exile. 1845 March 1: President John Tyler signs the official proposal of statehood for Texas. Mexican leaders warn that annexing Texas could lead to war. July 4: Texas legislators agree to annexation. July 25: General Zachary Taylor and his army arrive in Corpus Christi, Texas. December 6: John Slidell is sent to Mexico to offer $30 million for California, but his efforts are rebuffed. 1846 January 2: Mariano Paredes becomes President of Mexico.March 28: General Taylor reaches the Rio Grande near Matamoros.April 12: John Riley deserts and joins the Mexican army. Because he did so before war was officially declared, he could not legally be executed later when he was captured.April 23: Mexico declares defensive war against the United States: it would defend its territories under attack but not take the offensive.April 25: Captain Seth Thorntons small reconnaissance force is ambushed near Brownsville: this small skirmish would be the spark that kicked off the war.May 3–9: Mexico lays siege to Fort Texas (later renamed Fort Brown).May 8: Battle of Palo Alto is the first major battle of the war.May 9: Battle of Resaca de la Palma takes place, which results in Mexican army being forced out of Texas.May 13: US Congress declares war on Mexico.May: The St. Patricks Battalion is organized in Mexico, led by John Riley. It consisted largely of Irish-born deserters from the U S army, but there are also men of other nationalities. It would become one of Mexicos best fighting forces in the war. June 16: Colonel Stephen Kearny and his army leave Fort Leavenworth. They will invade New Mexico and California.July 4: American settlers in California declare the  Bear Flag Republic in Sonoma. The independent republic of California only lasted a few weeks before American forces occupied the area.July 27: Mexican President Paredes leaves Mexico City to deal with a revolt in Guadalajara. He leaves Nicols Bravo in charge.August 4: Mexican President Paredes is deposed by General Mariano Salas as chief executive of Mexico; Salas re-institutes federalism.August 13: Commodore Robert F. Stockton occupies Los Angeles, California with naval forces.August 16: Antonio Lopez de Santa Anna returns to Mexico from exile. The Americans, hoping he would promote a peace accord, had let him back in. He quickly turned on the Americans, stepping up to lead the defense of Mexico from the invaders.August 18: Kearny occupies Santa Fe, New Mexico.September 20–24: The Siege of Monterrey: Taylor capt ures the Mexican city of Monterrey. November 19: US President James K. Polk names Winfield Scott as leader of an  invasion force. Major General Scott was  a highly decorated veteran of the War of 1812 and the highest-ranking US military officer.November 23: Scott leaves Washington for Texas.December 6: Mexican Congress names Santa Anna President.December 12: Kearny occupies San Diego.December 24: Mexican General/President Mariano Salas turns over power to Santa Annas Vice-president, Valentà ­n Gà ³mez Farà ­as. 1847 February 22–23: The Battle of Buena Vista is the last major battle in the northern theater. The Americans will hold the ground they gained until the end of the war, but not advance any farther.March 9: Scott and his army land unopposed near Veracruz.March 29: Veracruz falls to Scotts army. With Veracruz under control, Scott has access to resupply from the USA.February 26: Five Mexican National Guard units (the so-called polkos) refuse to mobilize, rebelling against President Santa Anna and Vice-President Gà ³mez Farà ­as. They demand repeal of a law forcing a loan from the Catholic Church to the government.February 28: Battle of Rio Sacramento near Chihuahua.March 2: Alexander Doniphan and his army occupy Chihuahua.March 21: Santa Anna returns to Mexico City, takes control of the government and reaches an agreement with the rebellious polkos soldiers.April 2: Santa Anna leaves to fight Scott. He leaves Pedro Marà ­a Anaya in the Presidency.April 18: Scott defeats Santa Anna at the Battle of Cerro Gordo. May 14: Nicholas Trist, charged with eventually creating a treaty, arrives at Jalapa.May 20: Santa Anna returns to Mexico City, assumes the presidency once more.May 28: Scott occupies Puebla.August 20: The Battle of Contreras and the Battle of Churubusco open the way for the Americans to attack Mexico City. Most of the St. Patricks Battalion is killed or captured.August 23: Court-martial of members of St. Patricks Battalion at Tacubaya.August 24: Armistice is declared between US and Mexico. It would only last about two weeks.August 26: Court-martial of members of St. Patricks Battalion at San Angel.September 6: Armistice breaks down. Scott accuses Mexicans of breaking the terms and using the time on defenses.September 8: Battle of Molino del Rey.September 10: Sixteen members of St. Patricks Battalion are hanged at San Angel.September 11: Four members of St. Patricks Battalion are hanged at Mixcoac.September 13: Battle of Chapultepec: Americans storm gates into Mexico City. Thirty mem bers of St. Patricks Battalion hanged within sight of the castle. September 14: Santa Anna moves his troops out of Mexico City. General Scott occupies the city.September 16: Santa Anna is relieved of command. The Mexican government attempts to re-group in Querà ©taro. Manuel de la Peà ±a y Peà ±a is named President.September 17: Polk sends recall order to Trist. He receives it on November 16 but decides to remain and finish the treaty. 1848 February 2: Trist and Mexican diplomats agree on the  Treaty of Guadalupe Hidalgo.April: Santa Anna escapes from Mexico and goes into exile in Jamaica.March 10: The Treaty of Guadalupe Hidalgo is ratified by the USA.May 13: Mexican President Manuel de la Peà ±a y Peà ±a resigns. General Josà © Joaquà ­n de Herrera is named to replace him.May 30: The Mexican Congress ratifies the treaty.July 15: The last US troops depart Mexico from Veracruz. Sources and Further Reading Foos, Paul. A Short, Offhand, Killing Affair: Soldiers and Social Conflict During the Mexican-American War. Chapel Hill: University of North Carolina Press, 2002.Guardino, Peter. The Dead March: A History of the Mexican-American War. Cambridge: Harvard University Press, 2017.McCaffrey, James M. Army of Manifest Destiny: The American Soldier in the Mexican War, 1846-1848. New York: New York University Press, 1992.

Earths Elliptical Path Around the Sun

Earth's Elliptical Path Around the Sun Earths motion around the Sun was a mystery for many centuries as very early sky watchers attempted to understand what was actually moving: the Sun across the sky or Earth around the Sun. The Sun-centered solar system idea was deduced thousands of years ago by the Greek philosopher Aristarchus of Samos. It wasnt proved until Polish astronomer Nicolaus Copernicus proposed his Sun-centered theories in the 1500s, and showed how planets could orbit the Sun. Earth orbits the Sun  in a slightly flattened circle called an ellipse. In geometry, the ellipse is a curve that loops around two points called foci. The distance from the center to the longest ends of the ellipse is called the semi-major axis, while the distance to the flattened sides of the ellipse is called the semi-minor axis. The Sun is at one focus of each planets ellipse, which means that the distance between the Sun and each planet varies throughout the year.   Earths Orbital Characteristics When Earth is closest to the Sun in its orbit, it is at perihelion. That distance is 147,166,462 kilometers, and Earth gets there each January 3. Then, on July 4 of each  year, Earth is as far from the Sun as it ever gets, at a distance of 152,171,522 kilometers. That point is called aphelion. Every world (including comets and asteroids) in the solar system that primarily orbits the Sun has a perihelion point and an aphelion. Notice that for Earth, the closest point is during northern hemisphere winter, while the most distant point is northern hemisphere summer. Although theres a small increase in solar heating that our planet gets during its orbit, it doesnt necessarily correlate with the perihelion and aphelion. The reasons for the seasons are more due to our planets orbital tilt throughout the year. In short, each part of the planet tilted toward the Sun during the yearly orbit will get heated more during that time. As it tilts away, the heating amount is less. That helps contribute to the change of seasons more than Earths place in its orbit. Useful Aspects of Earths Orbit for Astronomers Earths orbit around the Sun is a benchmark for distance. Astronomers take the average distance between Earth and the Sun (149,597,691 kilometers) and use it as a standard distance called the astronomical unit (or AU for short). They then use this as shorthand for larger distances in the solar system. For example, Mars is 1.524 astronomical units. That means its just over one-and-a-half times the distance between Earth and the Sun. Jupiter is 5.2 AU, while Pluto is a whopping 39.,5 AU.   The Moons Orbit The Moons orbit is also elliptical. It moves around Earth once every 27 days, and due to tidal locking, always shows the same face to us here on Earth. The Moon doesnt actually orbit Earth; they actually orbit a common center of gravity called a barycenter. The complexity of the Earth-Moon orbit, and their orbit around the Sun results in the apparent changing shape of the Moon as seen from Earth. These changes, called phases of the Moon,  go through a cycle every 30 days. Interestingly, the Moon is slowly moving away from Earth. Eventually, it will be so far away that such events as total solar eclipses will no longer occur. The Moon will still occult the Sun, but it wont appear to block the entire Sun as it does now during a total solar eclipse. Other Planets Orbits The other worlds of the solar system that orbit the Sun have different length years due to their distances. Mercury, for example, has an orbit just 88 Earth-days long. Venuss is 225 Earth-days, while Marss is 687 Earth days. Jupiter takes 11.86 Earth years to orbit the Sun, while Saturn, Uranus, Neptune, and Pluto take 28.45, 84, 164.8, and 248 years, respectively. These lengthy orbits reflect one of Johannes Keplers laws of planetary orbits, which says that the period of time it takes to orbit the Sun is proportional to its distance (its semi-major axis). The other laws he devised describe the shape of the orbit and the time each planet takes to traverse each part of its path around the Sun. Edited and expanded by Carolyn Collins Petersen.