On May 12, the following notable historical events related to Missouri occurred:

• 1806: St. Louis, a growing Missouri outpost, supported spring trade with Native American tribes, though no specific event is noted.
• 1856: Missouri’s pro-slavery “Border Ruffians” raided Kansas anti-slavery settlers in “Bleeding Kansas,” intensifying territorial clashes in mid-May.
• 1861: Union General Henry W. Halleck in St. Louis reinforced federal control, while Confederate guerrillas in rural Missouri launched spring offensives, heightening state divisions.
• 1864: Confederate General Sterling Price’s Missouri forces in Arkansas geared up for spring operations, with Missouri remaining quiet under Union dominance.
• 1888: Southeast Missouri’s Missouri Pacific Railroad, linking Cape Girardeau to national markets, drove economic activity, with mid-May rail traffic surging.
• 1929: Missouri’s Kansas City and St. Louis faced Great Depression hardships, with spring relief initiatives creating jobs through infrastructure projects.
• 1941: Missouri’s St. Louis and Kansas City boosted World War II efforts, with factories expanding military output and mid-May recruitment drives gaining traction.