Cattle Egret much smaller with a shorter, stubbier bill and pale legs. Snowy Egret is smaller and has black bill and yellow feet. Immature Little blue Heron is smaller and has a pale bill with a black tip, and green legs. Reddish Egrets (white morph) have pale bills with black tips and blue-gray legs. The "Great White" Heron of southern Florida has yellow legs.
Length and wingspan from: Robbins, C.S., Bruun, B., Zim, H.S., (1966). Birds of North America. New York: Western Publishing Company, Inc.