[1] The bank was founded in 1960 and was located in the rear of the Penn Square Mall[2] in Oklahoma City.
The bank made its name in high-risk energy loans during the late 1970s and early 1980s Oklahoma and Texas oil boom.
[4] Unlike most previous bank failures since the Federal Deposit Insurance Corporation (FDIC) was formed, the uninsured depositors suffered losses as no other bank was willing to assume the deposits.
[5] The bank is often cited as being partly responsible for the collapse of Continental Illinois National Bank and Trust Company[6] of Chicago, which had to write off $326 million in loans purchased from Penn Square.
The insolvency was the subject of two best-selling books and led to a two-year prison term for the bank's energy-lending chief, Bill Patterson.