Gulf of Mexico numerous bays and smaller inlets. A number of rivers empty into the gulf, most notably the Mississippi River and Rio Grande in the northern gulf, and the Grijalva and Usumacinta rivers in the southern gulf. The land that forms the gulf's coast, including many long, narrow barrier islands, is almost uniformly low-lying and is characterized by marshes and swamps as well as stretches of sandy beach. The Gulf of Mexico is an excellent example of a passive margin. The continental shelf is quite wide at most points along the coast, most notably at the Florida and Yucatán Peninsulas. The shelf
Name of Mexico Caribbean and the Philippines. Since New Spain was not actually a state or a contiguous part of land, in modern times it would have been a jurisdiction under the command of the authorities in modern Mexico City. Under the Spaniards, Mexico was both the name of the capital and its sphere of influence, most of which exists as Greater Mexico City and the State of Mexico. Some parts of Puebla, Morelos and Hidalgo were also part of Spanish-era Mexico. In 1821, the continental part of New Spain seceded from Spain during the Trienio Liberal, in which Agustin de Iturbide marched