Gus Belt and the 1934 founding
Gus Belt founded Steak 'n Shake in February 1934. The original concept combined two then-distinct American food categories — steakburgers (ground-beef patties prepared from cuts of steak rather than from generic ground beef) and milkshakes — in a single counter-service restaurant format optimized for the auto-driven roadside dining market that was expanding rapidly during the Route 66 era. The combination of higher-quality burgers and dairy-rich milkshakes proved commercially successful and Belt began expanding the operation across central Illinois and into Missouri within the first few years.
The Springfield location is among the chain's first multi-state expansion restaurants, opened in the late 1930s as Belt extended Steak 'n Shake from its Illinois origins into Missouri's growing Route 66 corridor. Springfield's position on Route 66 — the highway that had been named in the city less than a decade earlier — made it a natural Steak 'n Shake target market. The original Springfield restaurant on East St. Louis Street has operated continuously since opening and is the chain's oldest Missouri location and one of its oldest restaurants overall.
The chain's expansion accelerated through the 1940s and 1950s as the post-World War II suburbanization and interstate highway construction produced the modern American car-culture dining market that Steak 'n Shake was designed for. The Gus Belt operating philosophy — "In Sight, It Must Be Right" — emphasized food preparation visible to customers from the dining counter, a feature that has been preserved at most Steak 'n Shake locations including the Springfield original.