Halloween costumes have advanced over the years. https://unsplash.com/photos/a-display-case-filled-with-lots-of-heads-of-people-ljvKcsN3hb4 Photo by Zain Creations on Unsplash loading... Now these are some fun Halloween costumes. The most popular Halloween costume in Massachusetts, Connecticut, and New York is the mermaid. You can check out the most popular Halloween costumes in each state by going here. LOOK: Classic Halloween costumes from 1865 to today Stacker scoured the archives to find 50 photos of Halloween costumes from 1865 to today.