In the mid to late 90s, the Federal Energy Regulatory Commission (FERC) made the decision to open the bulk electric system to competition. FERC established the competition rules by issuing Orders 888 and 889. The Commission followed up with an additional order, Order 2000, that encouraged utilities to turn operational control of their transmission lines to an independent agency.

In response to the FERC orders, a handful of Midwestern transmission owners joined together and established an independent entity to oversee the flow of wholesale electricity across the region. MISO (Midwest Independent System Operator) became the nation's first FERC-approved Regional Transmission Organization (RTO) on December 20, 2001. Later, in 2013, MISO expanded its region to include portions of four southern states, Arkansas, Mississippi, Louisiana, and Texas. This expansion resulted in MISO changing the “M” in its name from “Midwest” to “Midcontinent.”

Since its founding, MISO has managed the reliable flow of electricity across its territory. Facilitating the buying and selling of electricity within its region and planning the grid of the future are two additional roles MISO plays.