Interstate banking is spreading rapidly throughout the country. It is fairly well entrenched in the Southeast and in New England, and in 1985, interstate banking appeared in the Midwest with the passage of Indiana's regional interstate banking bill in April. In November, Illinois passed a similar law. Nevertheless, 26 states still prohibit interstate mergers and acquisitions. Over 9,500 institutions, representing 63 percent of all U.S. banking firms and 46 percent of domestic bank assets, are still forbidden to acquire or be acquired by bank holding companies across state lines.