Hi Lyle- Congratulations on seeing a shorebird in Memphis!
The overall look of this bird indicates a Tringa sandpiper. That's the genus. The legs have a yellow-green tinge. The Tringa shorebirds, known as the "shanks" in the UK often have colourful legs. The well-defined spots on the back and wings of this bird, the dull-yellow leg colour, and the relatively petit look suggest to me a Solitary Sandpiper, Tringa solitaria. The upper breast seems darker than normal though, and I am interested (as always) in other's opinions.
I'd go with Solitary Sandpiper as well. The very dark plumage (which makes the white spots really jump out), shortish legs, and white eye marks knock out the yellowlegs, Stilt Sandpiper, etc. To flip flop, the too long legs aren't right for Spotted. Ditto for the dark plumage and white spotting.