Lakeshore Learning Store. It was worth the investment! They have been an excellent resource as we've studied U.S. History this year. My children have been introduced to and have discovered some of the most important people in American History, and they can now recognize the contributions of these significant individuals. Each card features an illustration on the front and biographical facts on the back.
I posted awhile back about how I use History cards in some of our daily learning activities. We've used these Biographical cards in similar ways.