Lovely gown, and I so agree with Nicole. I'm seeing late 50s to early 60s, too. That bodice style, both the waistline and the bow treatment, was really popular around then; I've had many, many dresses with it. Some were definitely 50s, with the underarm gussets, others a toss-up between 50s and 60s. The neckline could be either too, I think.