Question: In 1823, what emperor was overthrown in the country that the US bought land from in the Gadsden Purchase?

full_context: Document 1: Federal Republic of Central America: Shortly after Central America declared independence from the Spanish Empire, some of its countries were annexed by the First Mexican Empire in 1822 and then Central America formed the Federal Republic in 1823. From 1838 to 1840 the federation descended into civil war, with conservatives fighting against liberals and separatists fighting to secede. The various political factions were unable to overcome their ideological differences and the federation dissolved after a series of bloody conflicts.
Document 2: Chihuahua (state): Hidalgo is hailed as the Father of the Nation even though it was Agustin de Iturbide and not Hidalgo who achieved Mexican Independence in 1821. Shortly after gaining independence, the day to celebrate it varied between September 16, the day of Hidalgo's Grito, and September 27, the day Iturbide rode into Mexico City to end the war. Later, political movements would favor the more liberal Hidalgo over the conservative Iturbide, so that eventually September 16, 1810 became the officially recognized day of Mexican independence. The reason for this is that Hidalgo is considered to be "precursor and creator of the rest of the heroes of the (Mexican War of) Independence." Hidalgo has become an icon for Mexicans who resist tyranny in the country. Diego Rivera painted Hidalgo's image in half a dozen murals. José Clemente Orozco depicted him with a flaming torch of liberty and considered the painting among his best work. David Alfaro Siqueiros was commissioned by San Nicolas University in Morelia to paint a mural for a celebration commemorating the 200th anniversary of Hidalgo's birth. The town of his parish was renamed Dolores Hidalgo in his honor and the state of Hidalgo was created in 1869. Every year on the night of 15–16 September, the president of Mexico re-enacts the Grito from the balcony of the National Palace. This scene is repeated by the heads of cities and towns all over Mexico. The remains of Miguel Hidalgo y Costilla lie in the column of the Angel of Independence in Mexico City. Next to it is a lamp lit to represent the sacrifice of those who gave their lives for Mexican Independence.
Document 3: Abolition of monarchy: In 1858 the Mughal Empire came to an end after losing a war against Britain, and its Emperor, Bahadur Shah II, lost his throne. Between 1859 and 1861, four monarchies in Southern Europe ceased to exist: Parma, Modena, Tuscany and the Two Sicilies, when they all became part of the new Kingdom of Italy. The Second Mexican Empire collapsed in 1867, and its Emperor, Maximilian I of Mexico, was executed. The Second French Empire came to an end in 1870 after it had lost the war against Prussia, causing Emperor Napoleon III to lose his throne. He was the last monarch of France.
Document 4: First Mexican Empire: It existed from the signing of the Treaty of Córdoba and the declaration of Independence of the Mexican Empire in September 1821 until the emperor's abdication in March 1823 when the Provisional Government took power and the First Mexican Republic was proclaimed in 1824. The first and only monarch of the state was Agustín de Iturbide, reigning as Agustín I of Mexico, for less than eight months. The empire was briefly reestablished by the French in 1863.
Document 5: Tucson, Arizona: Arizona, south of the Gila River was legally bought from Mexico in the Gadsden Purchase on June 8, 1854. Tucson became a part of the United States of America, although the American military did not formally take over control until March 1856. In 1857 Tucson became a stage station on the San Antonio-San Diego Mail Line and in 1858 became 3rd division headquarters of the Butterfield Overland Mail until the line shut down in March 1861. The Overland Mail Corporation attempted to continue running, however following the Bascom Affair, devastating Apache attacks on the stations and coaches ended operations in August 1861.[citation needed]
Document 6: Tucson, Arizona: Tucson is commonly known as "The Old Pueblo". While the exact origin of this nickname is uncertain, it is commonly traced back to Mayor R. N. "Bob" Leatherwood. When rail service was established to the city on March 20, 1880, Leatherwood celebrated the fact by sending telegrams to various leaders, including the President of the United States and the Pope, announcing that the "ancient and honorable pueblo" of Tucson was now connected by rail to the outside world. The term became popular with newspaper writers who often abbreviated it as "A. and H. Pueblo". This in turn transformed into the current form of "The Old Pueblo".
Document 7: Chihuahua (state): Under threat from the conservative forces, Governor Terrazas was deposed, and the state legislature proclaimed martial law in the state in April 1864 and established Jesús José Casavantes as the new governor. In response, José María Patoni decided to march to Chihuahua with presidential support. Meanwhile, Maximilian von Habsburg, a younger brother of the Emperor of Austria, was proclaimed Emperor Maximilian I of Mexico on April 10, 1864 with the backing of Napoleon III and a group of Mexican conservatives. Before President Benito Juárez was forced to flee, Congress granted him an emergency extension of his presidency, which would go into effect in 1865 when his term expired, and last until 1867. At the same time, the state liberals and conservatives compromised to allow the popular Ángel Trías take the governorship; by this time the French forces had taken control over the central portions of the country and were making preparations to invade the northern states.
Document 8: Gadsden Purchase: The Gadsden Purchase (known in Mexico as Spanish: Venta de La Mesilla, ``Sale of La Mesilla '') is a 29,670 - square - mile (76,800 km) region of present - day southern Arizona and southwestern New Mexico that the United States purchased via a treaty signed on December 30, 1853, by James Gadsden, U.S. ambassador to Mexico at that time. The U.S. Senate voted in favor of ratifying it with amendments on April 25, 1854, and then transmitted it to 14th President Franklin Pierce. Mexico's government and its General Congress or Congress of the Union took final approval action on June 8, 1854. The purchase was the last substantial territorial acquisition in the contiguous United States. The U.S. sought the land as a better route for the construction of the southern transcontinental railway line, and the financially - strapped government of Antonio López de Santa Anna agreed to the sale, which netted Mexico $10 million (equivalent to $270 million in 2017). After the devastating loss of Mexican territory to the U.S. in the Mexican -- American War (1846 -- 48) and the continued filibustering by U.S. citizens, Santa Anna may have calculated it was better to yield territory by treaty and receive payment rather than have the territory simply seized by the U.S.
Document 9: Tucson, Arizona: Jesuit missionary Eusebio Francisco Kino visited the Santa Cruz River valley in 1692, and founded the Mission San Xavier del Bac in 1700 about 7 mi (11 km) upstream from the site of the settlement of Tucson. A separate Convento settlement was founded downstream along the Santa Cruz River, near the base of what is now "A" mountain. Hugo O'Conor, the founding father of the city of Tucson, Arizona authorized the construction of a military fort in that location, Presidio San Agustín del Tucsón, on August 20, 1775 (near the present downtown Pima County Courthouse). During the Spanish period of the presidio, attacks such as the Second Battle of Tucson were repeatedly mounted by Apaches. Eventually the town came to be called "Tucson" and became a part of Sonora after Mexico gained independence from Spain in 1821.
Document 10: Gadsden Purchase: The Gadsden Purchase (known in Mexico as Spanish: Venta de La Mesilla, ``Sale of La Mesilla '') is a 29,670 - square - mile (76,800 km) region of present - day southern Arizona and southwestern New Mexico that the United States purchased via a treaty signed on December 30, 1853, by James Gadsden, U.S. ambassador to Mexico at that time. The U.S. Senate voted in favor of ratifying it with amendments on April 25, 1854, and then transmitted it to 14th President Franklin Pierce. Mexico's government and its General Congress or Congress of the Union took final approval action on June 8, 1854. The purchase was the last substantial territorial acquisition in the contiguous United States. The U.S. sought the land as a better route for the construction of the southern transcontinental railway line, and the financially - strapped government of Antonio López de Santa Anna agreed to the sale, which netted Mexico $10 million (equivalent to $270 million in 2017). After the devastating loss of Mexican territory to the U.S. in the Mexican - American War (1846 -- 48) and the continued filibustering by U.S. citizens, Santa Anna may have calculated it was better to yield territory by treaty and receive payment rather than have the territory simply seized by the U.S.
Document 11: Treaty of Guadalupe Hidalgo: With the defeat of its army and the fall of its capital, Mexico entered into negotiations to end the war. The treaty called for the U.S. to pay US $15 million to Mexico and to pay off the claims of American citizens against Mexico up to US $5 million. It gave the United States the Rio Grande as a boundary for Texas, and gave the U.S. ownership of California and a large area comprising roughly half of New Mexico, most of Arizona, Nevada, and Utah, and parts of Wyoming and Colorado. Mexicans in those annexed areas had the choice of relocating to within Mexico's new boundaries or receiving American citizenship with full civil rights.
Document 12: Mexican War of Independence: On September 27, 1821 the Army of the Three Guarantees entered Mexico City, and the following day Iturbide proclaimed the independence of the Mexican Empire, as New Spain was henceforth to be called. The Treaty of Córdoba was not ratified by the Spanish Cortes. Iturbide included a special clause in the treaty that left open the possibility for a criollo monarch to be appointed by a Mexican congress if no suitable member of the European royalty would accept the Mexican crown. Half of the new government employees appointed were Iturbide's followers.
Document 13: Mexican War of Independence: The Mexican War of Independence (Spanish: Guerra de Independencia de México) was an armed conflict, and the culmination of a political and social process which ended the rule of Spain in 1821 in the territory of New Spain. The war had its antecedent in Napoleon's French invasion of Spain in 1808; it extended from the Grito de Dolores by Father Miguel Hidalgo y Costilla on September 16, 1810, to the entrance of the Army of the Three Guarantees led by Agustín de Iturbide to Mexico City on September 27, 1821. September 16 is celebrated as Mexican Independence Day.
Document 14: Confederate Arizona: Confederate Arizona, commonly referred to as Arizona Territory, and officially the Territory of Arizona, was a territory claimed by the Confederate States of America during the American Civil War, between 1861 and 1865. Delegates to secession conventions had voted in March 1861 to secede from the New Mexico Territory and the United States, and seek to join the Confederacy. It consisted of the portion of the New Mexico Territory south of the 34th parallel, including parts of the modern states of New Mexico and Arizona. Its capital was Mesilla along the southern border. The Confederate territory overlapped the Arizona Territory later established by the Union government in 1863.
Document 15: Tucson, Arizona: Tucson is located 118 mi (190 km) southeast of Phoenix and 60 mi (97 km) north of the United States - Mexico border. The 2010 United States Census puts the city's population at 520,116 with a metropolitan area population at 980,263. In 2009, Tucson ranked as the 32nd largest city and 52nd largest metropolitan area in the United States. A major city in the Arizona Sun Corridor, Tucson is the largest city in southern Arizona, the second largest in the state after Phoenix. It is also the largest city in the area of the Gadsden Purchase. As of 2015, The Greater Tucson Metro area has exceeded a population of 1 million.
ground_truth: Agustín de Iturbide
sub_queries: Where did the US buy land from in the Gadsden Purchase? Answer: Mexico
who was the emperor of Mexico who was overthrown in 1823 Answer: Agustín de Iturbide