Mississippi River floods among the largest and most damaging along the U.S. waterway in the past century, rivalling major floods in 1927 and 1993. In April 2011, two major storm systems dumped record rainfall on the Mississippi River watershed. Rising from springtime snowmelt, the river and many of its tributaries began to swell to record levels by the beginning of May. Areas along the Mississippi itself experiencing flooding include Illinois, Iowa, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana. U.S. President Barack Obama declared the western counties of Kentucky, Tennessee, and Mississippi federal disaster areas. For the second time in 38 years, the Morganza
6th Missouri Volunteer Cavalry May 18-July 4. Assaults on Vicksburg May 19 and 22. Mason's Ford. Big Black River, June 9. Advance on Jackson, Miss., July 4–10. Near Baker's Creek July 7. Bolton's Station July 8 (detachment). Near Clinton July 8 (detachment). Near Jackson and near Clinton July 9 (detachment). Siege of Jackson July 10–17. Brookhaven July 18 (detachment). Near Morganza, La., September 8. Atchafalaya September 8–9. Hornersville, Mo., September 20 (2nd Battalion). Sterling's Farm, on Bayou Fordoche, near Morganza, September 27. Western Louisiana Campaign October 3-November 30. Reconnaissance toward Opelousas October 20. Opelousas, Barre Landing, October 21. Washington October 24. Bayou Bourbeaux November