 Each bank and credit union has a unique routing number so that people and machines that process the checks know where the money is supposed to go and where it's supposed to come from. There's no confusing institutions with similar names such as Bank of America and American Bank. Routing numbers date all the way back to 1910. The Bankers Association came up with them to help make check processing easier and safer. The numbers became part of electronic check cashing when that came along in the 1960s.