I finally found what I wanted to display our postcards and also to show Princess where all the states are! The map is actually a place mat, but I think it works quite well. The colors make it easier to see each state, and more pleasing to look at! I used white yarn to connect the thumb tacks from the state on the map to the post card. I wanted different colored thumb tacks but couldn't find any.
(Sorry about the glare, its a place mat so its laminated. Click the picture to make it bigger)(I just noticed, apparently the date is wrong on my camera, oops, I took this picture today)