Sedalia has a long history with the railroad. City founder General George R. Smith founded the city to attract the Pacific Railroad to the community after neighboring Georgetown failed to secure an investment. The city itself is named after Smith’s daughter Sarah, whose nickname was Sed. The city did not begin to prosper until January 1861.

In 1860, the Missouri legislature chartered the Tebo & Neosho Railroad Company to build a line between Neosho, Missouri, and the site of what would eventually become Sedalia. The Civil War put the plans of Tebo & Neosho on hold as all available resources and manpower were funneled toward the conflict. In 1866 and upon the conclusion of the war, the legislature amended the charter to set the terminus of the line at Fort Scott, Kansas, instead of Neosho.

1870 saw the first passenger train departure from Sedalia. The Missouri, Kansas & Texas - known as MK&T or Katy - line, partnered with and later absorbed the Tebo & Neosho line. The MKT provided service between Sedalia and Clinton, Missouri. Crowds cheered all along the forty-mile route between the cities as the line provided MK&T a vital link between their western operations and cities in the east. Construction crews returned to Sedalia in 1873 and lines were built to link Sedalia and St. Louis.

Sedalia's now-historic Katy Depot was constructed in 1896 on what would later become Third Street. As one of the largest MK&T depots between St. Louis and Kansas City, the Sedalia depot featured a dining room and second-story offices. Local newspapers promoted the depot as proof of Sedalia's importance to the railroad industry.

Railroad strikes in the early 1920s weakened the Sedalia economy and the Great Depression sealed the fate of Sedalia's MK&T shops. They would close permanently by 1940. The decline in demand for passenger train service, fueled by the growth of the automotive industry, impacted MK&T and in May 1958, the last MK&T passenger train passed through Sedalia.

Made of red brick and limestone, the historic Katy Depot is the only structure remaining as a reminder of MK&T's once-extensive passenger operations in the city. The depot was renovated between the years of 1998 and 2001 and now serves as the offices of both the Chamber of Commerce and the Convention & Visitor's Bureau. The Katy Depot is located at 600 East Third Street and is open to the public on weekdays from 9 a.m. through 5 p.m.