1982: National Convenience Stores (NCS) goes public with more than 800 stores, becomes a consolidator.
1983: A merger creates refiner-marketer Diamond Shamrock with 600 service stations.
1990: Circle K and 7-Eleven both file for bankruptcy; 7-Eleven emerges in 1991, Circle K in 1993; NCS pares down, sells off stores in select markets to Mapco, Diamond Shamrock and BP.
1991: NCS files for bankruptcy, emerges in 1993.