After he had successfully remodeled the station into a convenience store and operated it for nine years, his gasoline supplier and friend, Kurvin C.

Fish, suggested that he purchase the Square Deal Oil Company, a service station available for sale in Boone, Iowa.

[9] Lamberti became more ambitious and decided to open a store from scratch in the even smaller town of Waukee, Iowa (population 1,500 at the time).

[13][14][15] On August 7, 2006, Casey's agreed to purchase the 33-store HandiMart chain, based in Cedar Rapids, Iowa, in a $63 million deal.

[23] Casey's announced plans in August 2018 to build a store in Huber Heights, Ohio.

[25] In October 2020, Casey's announced a rebranding, including a new logo and dropping 'General Stores' from its signage (though it remained in the legal corporate name until 2022).

The locations in East Tennessee, around the Knoxville area, were owned by the Haslam family outright and not part of the company's national truck stop chain jointly-owned by Pilot, Berkshire Hathaway, and FJ Management.

[35] In July 2024 Casey's purchased Fikes Wholesale, Inc., including its chain of CEFCO convenience stores, in a $1.145B all-cash transaction.

The deal, which closed in November 2024, added nearly 200 stores and expanded Casey's further into Texas as well as for the first time into the states of Alabama, Florida, and Mississippi.