The older one is rayon, probably 1940s. I absolutely love the color combo in the print! The dress has shoulder pads, self-covered buttons, and - my favorite detail - velvet covered piping at the collar and sleeves.
The lovely styling and detailing make this another piece that reminds me how much simpler off-the-rack clothing has become since that era.
The second dress is cotton and from the 1950s, or maybe around 1960. It's a bit more tailored than the first dress, with a front placket and roll cuffed sleeves. I love it because of its great conversation print. It just plain makes me smile!