Tried researching this one a bit - just coming up with 1880s. Am I close? I'm guessing perhaps there was something at one point to make the bustle more full? It seems deflated. Also, the pointy front and back of the bodice seems off? Thank you as always!
I would have to handle it to be more specific, but I think early 80s 1881-83. If it were earlier, the bodice would be cut longer in the back, and if newer, the bodice would be cut shorter in the back. Hollis might weigh in on this... It was probably a wedding dress, blue was the second colour choice of most brides in the 19th century -- more practical.
I think Jonathan's right with very early 1880s. The 3/4 sleeve and that little pocket on the side of the bodice are something I associate with earlier 1880s as well. And yes, Linda is on it. A wire bustle frame for lift, although not at the most extreme shelf projection of the later 1880s.