1987 - Evangel College (now Evangel University) joined the HAAC in the 1987-88 academic year.1986 - Central Methodist left the HAAC to become an NAIA Independent after the 1985-86 academic year.1982 - Ottawa left the HAAC to re-join the Kansas Collegiate Athletic Conference (KCAC) after the 1981-82 academic year.1980 - Culver–Stockton College and Mid-America Nazarene College (now MidAmerica Nazarene University) joined the HAAC in the 1980-81 academic year.1974 - The College of Emporia left the HAAC as the school announced that it would close after the 1973-74 academic year.Charter members included Baker University, Central Methodist College (now Central Methodist University), the College of Emporia, Graceland College (now Graceland University), Missouri Valley College, Ottawa University, Tarkio College and William Jewell College beginning the 1971-72 academic year. 1971 - The Heart of America Athletic Conference (HAAC) was founded.Thomas, the first female commissioner in NAIA history, began her term in 2014, succeeding Larry Lady who retired after 22 years as commissioner. The current commissioner of the conference is Lori Thomas. On February 10, 2022, long-serving Evangel University accepted its invitation to join the Kansas Collegiate Athletic Conference, also Kansas-based, in 2023–24. In October 2019, Park University was approved for HAAC membership and joined in the 2020–21 school year.

In April 2015, Clarke University and Mount Mercy University were also announced as members for the 2016–17 school year. In early 2014, Grand View University and William Penn University were announced as members for the 2015–16 school year. However, the HAAC does not presently claim the Athletic Union's history as its own.

It was reorganized as the HAAC in 1971 when it began admitting schools outside Missouri. The old MIAA's private schools formed the Athletic Union, while the state teachers' colleges stayed in the MIAA. The HAAC's earliest ancestor was the Missouri College Athletic Union (MCAU), which was formed in 1924 when the Missouri Intercollegiate Athletic Association (now the Mid-America Intercollegiate Athletics Association or MIAA) split in two.

Heart of america conference