sentences:  First Chicago was not able to open its first branch bank until 1977, when banks were allowed to open two limited banking facilities within 1,500 feet of the main office.Unlike its rivals, First Chicago waited two years before making its first bank purchase after the Illinois legislature began to allow holding companies to own more than one bank in 1981.In 1984, First Chicago purchased American National Corporation, the holding company for American National Bank and Trust Company of Chicago, another bank located in the Loop, from Walter E. Heller International Corporation for $275 million.