Mexican Cession Mexican Cession, with considerable local autonomy punctuated by several revolts and few troops sent from central Mexico, in the period from 1821–22 after independence from Spain up through 1846 when U.S. military forces seized control of California and New Mexico on the outbreak of the Mexican–American War. The northern boundary of the 42nd parallel north was set by the Adams–Onís Treaty signed by the United States and Spain in 1821 and ratified by Mexico in 1831. The eastern boundary of the Mexican Cession was the Texas claim at the Rio Grande and extending north from the headwaters of the Jojo
Battle of the Trench (1821) before. Battle of the Trench (1821) The Battle of the Trench () was fought near Tripolitsa in Arcadia in August 1821 during the first year of the Greek War of Independence between the Greek revolutionary forces led by Theodoros Kolokotronis and the Ottoman garrison of Tripolitsa. The battle ended with the complete victory of the Greeks. In August 1821, Greeks began the siege of Tripolitsa. The Ottomans who were besieged in the city attempted several night sallies in order to find supplies. When Theodoros Kolokotronis was called by the besiegers to take over command of the siege, he therefore ordered