|Middle Atlantic Conferences|
|Members||17 (9, MAC Commonwealth; 8, MAC Freedom)|
|Former names||Middle Atlantic States Collegiate Athletics Association|
Middle Atlantic States Collegiate Athletic Conference
The organization is divided into two main conferences: the MAC Commonwealth and the MAC Freedom. A third conference, named the Middle Atlantic Conference (singular), draws members from both the Commonwealth and Freedom conferences and sponsors sports that only a certain set of members participate in, such as track & field and cross country.
In 1912, the Middle Atlantic States Collegiate Athletics Association (MASCAA) was founded primarily as a track association and had its first event, a track meet, at Lafayette College in May 1913. In 1922, it was reorganized as the Middle Atlantic States Collegiate Athletic Conference (MASCAC or MAC). The original 13 members present at the formation meeting in 1922 were: Bucknell University, Drexel University, Franklin & Marshall College, Gettysburg College, Haverford College, Muhlenberg College, New York University, Princeton University, Rutgers University, Stevens Institute of Technology, Susquehanna University, Swarthmore College, and the University of Delaware. In addition, another five members who were not present at the initial meeting but formally approved of the plan were: Columbia University, Johns Hopkins University, Lehigh University, Ursinus College, and Widener University.
Throughout its history, the organization has had at least 50 different members associated with it. The conference had as many as 37 members at one time in the late 1950s. A major reduction in the league occurred in 1974 after the NCAA created Divisions I, II, and III. At that time, 11 members left to form the Division I East Coast Conference and by 1976, the MAC became fully associated with Division III. An additional 11 members left in 1992 to form the Centennial Conference; the football programs for eight of those schools had already left in 1981. In 1999, the current corporation formed with its three conferences: MAC Commonwealth, MAC Freedom, and Middle Atlantic.
Arcadia University and Manhattanville College joined MAC Freedom for 2007–08. They replaced Juniata College, Drew University, Moravian College, Susquehanna University, and the University of Scranton, who left to join the new Landmark Conference. To offset the change in numbers, it was also decided to switch Lycoming College from the MAC Freedom to the MAC Commonwealth.
Alvernia University, Misericordia University, and Eastern University, all from the Pennsylvania Athletic Conference, accepted membership in the MAC Freedom and started participation in the 2008–09 school year. Starting in the 2009–10 school year, Alvernia switched from the MAC Freedom to the MAC Commonwealth, thereby giving the Commonwealth and Freedom leagues the same number of members.
Stevenson University and Hood College accepted invitations to join the MAC and MAC Commonwealth starting with the 2012–13, expanding the conference to 18 members.  Elizabethtown College moved to the Landmark Conference for 2014–15. In May 2018, Manhattanville College announced that they would leave the MAC Freedom Conference and return to the Skyline Conference for the 2019–20 academic year. Manhattanville was a charter member of the Skyline before leaving to join the MAC in 2007.  Three months later, the MAC announced that Stevens Institute of Technology, which had left the conference in 1978, would return in 2019–20 and replace Manhattanville in the MAC Freedom. In April 2019, the MAC announced that York College of Pennsylvania would join the MAC Commonwealth in 2020–21.
In May 2019, the MAC announced it would realign the Commonwealth and Freedom conferences into two equally-sized leagues effective with York's arrival in 2020. Arcadia and Lycoming will move from the MAC Commonwealth to the MAC Freedom, while Eastern will make the opposite move.
In 1958, the MAC began sponsoring football. The football conference essentially operated as two separate conferences with the larger schools (Delaware, Temple, Lafayette, Lehigh, Bucknell, Gettysburg, and Rutgers) playing a round-robin schedule, and the smaller schools (Juniata, Lycoming, Wilkes, Widener, and Albright) playing a separate round-robin schedule. Although the upper division of the conference (which also included Muhlenberg, Drexel, La Salle, and Saint Joseph's) competed at the Division I (then known as the University Division) level in other sports, only Rutgers was considered a University Division football school. Following the 1969 season, the upper level of MAC football was disbanded as Temple dropped out to upgrade their football schedule. Rutgers had previously dropped out of the MAC for all sports and a five-team football league was not desirable. The lower division continued as MAC football, but Delaware, Lafayette, Lehigh, Gettysburg, and Bucknell operated as football independents for the rest of their tenure with the league. Numerous other MAC schools competed in other football leagues throughout most of the league's history.
In 1983, the Centennial Football League was formed by 8 MAC members. Eventually, those 8 schools and two others broke apart from the MAC for all sports, founding the Centennial Conference in 1991. Since then, all league members that sponsor football have competed in the MAC Football Conference.
|Albright College||Reading, Pennsylvania||Lions||1856||Private/Methodist||2,304||1945‡|
|Alvernia University||Reading, Pennsylvania||Golden Wolves||1958||Private/Catholic||2,872||2008|
|Arcadia University||Glenside, Pennsylvania||Knights||1853||Private/Presbyterian||2,473||2007|
|Hood College||Frederick, Maryland||Blazers||1893||Private/Reformed||1,174||2012|
|Lebanon Valley College||Annville, Pennsylvania||Flying Dutchmen||1866||Private/Methodist||1,712||1945‡|
|Lycoming College||Williamsport, Pennsylvania||Warriors||1812||Private/Methodist||1,272||1952|
|Messiah College||Grantham, Pennsylvania||Falcons||1909||Private/Christian||3,305||1983|
|Stevenson University||Stevenson, Maryland||Mustangs||1947||Private/Non-sectarian||3,621||2012|
|Widener University||Chester, Pennsylvania||Pride||1821||Private/Non-sectarian||6,402||1946‡|
- ‡ — Conference records prior to 1946 are incomplete so years given are the earliest known that were officially recorded.
|Delaware Valley University||Doylestown, Pennsylvania||Aggies||1896||Private/Nonsectarian||2,375||1965|
|DeSales University||Center Valley, Pennsylvania||Bulldogs||1965||Private/Catholic||3,309||1997|
|Eastern University||St. Davids, Pennsylvania||Eagles||1952||Private/Baptist||3,420||2008|
|Fairleigh Dickinson University-Florham||Madison, New Jersey||Devils||1942||Private/Nonsectarian||2,546||1977|
|King's College||Wilkes-Barre, Pennsylvania||Monarchs||1946||Private/Catholic||2,421||1977|
|Misericordia University||Dallas, Pennsylvania||Cougars||1924||Private/Catholic||2,879||2008|
|Stevens Institute of Technology||Hoboken, New Jersey||Ducks||1870||Private/Nonsectarian||5,260||2019[a]|
|Wilkes University||Wilkes-Barre, Pennsylvania||Colonels||1933||Private/Nonsectarian||5,552||1946[b]|
Enrollment source: 
- This is Stevens' second stint as a MAC member. Because it was represented at the original MAC formation meeting in 1922, it is often regarded as a founding member. While conference records before 1946 are incomplete, Stevens is officially listed as having been a conference member in 1946, and remained a member until 1978.
- Conference records prior to 1946 are incomplete so years given are the earliest known that were officially recorded.
Member teams currently compete in 27 sports, 14 men's and 13 women's. The most recently added sports are men's and women's ice hockey and men's volleyball, all added for 2017–18. The MAC now sponsors all NCAA Division III sports except women's rowing.
|Track & field (indoor)|
|Track & field (outdoor)|
Middle Atlantic Conference
The Middle Atlantic Conference combines schools from both the MAC Commonwealth and MAC Freedom and is currently used for cross country, football, ice hockey, track & field (indoor / outdoor), swimming, men's volleyball, and wrestling. Future member York is indicated in gray.
- Adding men's and women's ice hockey in 2021–22.
- "A History of the Middle Atlantic Conferences" (PDF). Middle Atlantic Conferences. August 4, 2010. Archived (PDF) from the original on November 7, 2017. Retrieved November 7, 2017.
- "Latest News". NCAA.org. Archived from the original on 2012-08-13. Retrieved 2011-07-06.
- "Manhattanville to Join Skyline Conference in 2019-20 Academic Year". Skyline Conference. Skyline Conference. Archived from the original on 12 May 2018. Retrieved 11 May 2018.
- "MAC Welcomes Stevens Institute of Technology Back in 2019-20" (Press release). Middle Atlantic Conferences. August 15, 2018. Archived from the original on October 2, 2018. Retrieved October 1, 2018.
- "MAC to Add York (Pa.) as 18th Member Beginning in 2020-21" (Press release). Middle Atlantic Conferences. April 2, 2019. Archived from the original on April 23, 2019. Retrieved April 22, 2019.
- "MAC Announces Realignment for 2020-21" (Press release). Middle Atlantic Conferences. May 7, 2019. Archived from the original on August 6, 2019. Retrieved August 5, 2019.
- "Best Colleges". U.S. News & World Report. Archived from the original on 2018-03-13. Retrieved 2017-11-07.
- "History". Middle Atlantic States Collegiate Athletic Corporation. Retrieved 2008-09-19.
- "MAC to Sponsor Ice Hockey and Men's Volleyball Beginning 2017-18" (Press release). Middle Atlantic Conferences. October 12, 2016. Archived from the original on February 2, 2017. Retrieved January 22, 2017.
- "Middle Atlantic Conference". D3Football.com. Archived from the original on December 21, 2008. Retrieved 2008-09-19.