After trading for 25 years on the New York Stock Exchange, where it was known as Speedway Motorsports, Inc. (SMI), the company was taken private in September 2019, and today is a wholly owned subsidiary of Sonic Financial Corporation, itself owned by members of Bruton Smith's family.

Bruton Smith began building SMI in the 1950s when he worked as a race promoter and eventually built Charlotte Motor Speedway in 1959.

[1] In 1996, SMI began to quickly expand, acquiring two additional facilities; Bristol Motor Speedway and Sonoma Raceway.

That same year, SMI sold the naming rights of its flagship Charlotte Motor Speedway to Lowe's, a $35 million deal that would last until 2009.

The $623 million deal propelled ISC to the top track owner, and SMI fell to second.

In December 2018, Nashville Fairgrounds Speedway operator Tony Formosa Jr. reached an agreement with Speedway Motorsports and its main Tennessee track Bristol Motor Speedway to co-operate the facility and make the necessary upgrades for the track to host NASCAR Xfinity Series and NASCAR Camping World Truck Series races again and continue to host weekly racing events.

[3] Efforts were renewed in late 2020 as SMI and Bristol launched negotiations with the City of Nashville with the goal of hosting NASCAR races as early as 2022.

The company's purchases and closures of the tracks in order to obtain a second NASCAR date for Texas Motor Speedway led to the Ferko lawsuit.

This has led to speculation that SMI would move one of New Hampshire's dates to Las Vegas Motor Speedway and/or swap the date with the fall race at Texas Motor Speedway (TMS has expressed an interest in moving the fall race away from the first weekend in November, which is also the opening weekend of deer hunting season in Texas).

[7] SMI was finally victorious in their pursuit, with Kentucky Speedway receiving its inaugural Sprint Cup race on July 9, 2011.

[8] It appears this came at the expense of SMI-owned Atlanta Motor Speedway, which dropped from two races to one on the 2011 Sprint Cup schedule.

Dover Motorsports also operated Nashville Superspeedway, a 1.333-mile concrete oval track in Lebanon, Tennessee.

Dover also owned Gateway International Raceway, a 1.25-mile egg-shaped asphalt oval track in Madison, Illinois, which was sold in 2011.