Azcapotzalco (äskäpōtsälˈkō) [key], city (1990 pop. 473,476), S Mexico, in the Federal District. An important rail center, with railroad yards, it is the terminus of mail and cargo traffic. Azcapotzalco's cattle industry supplies the bulk of Mexico City's dairy products. Other industries include auto assembling, oil refining, and the manufacture of textiles, paper, and records. The city was a leading cultural center in the pre-Columbian period. During Mexico's War of Independence, it was the site (1821) of a major battle in which loyalist troops were forced to retreat by the revolutionary soldiers. Azcapotzalco is noted for its baroque colonial architecture and its 18th-century churches.