The Mississippi River is known as the Middle Mississippi from the Upper Mississippi River's confluence with the Missouri River at St. Louis, Missouri, for 190 miles (310 km) to its confluence with the Ohio River at Cairo, Illinois. The Middle Mississippi is relatively free-flowing.
As Hopper notes, eight major U.S. airlines offer free cancellation for tickets purchased at least seven days in advance: Delta, United, US Airways, JetBlue, Southwest, Spirit, Frontier and American (in American 's case, you'll hold your ticket instead of purchasing it).
I wouldnât bank on this working out in your favor, but as I often say â it never hurts to ask. If youâre at risk of incurring a ticket change fee, donât be afraid to ask United â or other major airline â for a break. You could also simply wait until the day of departure to see if the flight gets cancelled or delayed. In either case, you might be able to get a full refund, penalty-free. Or if thereâs a big storm and the airline extends weather waivers, you may be able to postpone your ticket free of charge.