Sounds like the chewed up gunk from the disposal has largely blocked the drain pipe. Try a plunger first (block all other connected drains) but that may or may not be effective depending on how far along the clog is.
If the simple solution doesn't work, you'll have to open a clean-out (or the U-trap) and use an auger to break it out. You can rent a "snake" from Home Depot that attaches to a power drill.
As @Chris Cudmore said, avoid fibrous material. Corn husks are the worst.
Important: If this happens again, you may have a plumbing problem! Disposals are often connected to existing plumbing that is not sufficient to handle them. The drain should be 2" pipe with limited slope (or vertical) and must be the direct path to the main sewer with any other connections merging into the pipe from above. Otherwise, you get places where the gunk can stick for a moment and have water move back along the other path giving time for the gunk to stick even more until you basically have concrete blocking your pipe. I'll give you 3 guesses as to how I know this... and the first two don't count.