I found similar cards last year for the Ancients, but couldn't find anything for American History. Even if you don't use HOD these cards will cover many of the early American history figures you would study. You can find the file for these cards here in Google Docs. The files are also located here or here if you have trouble with the first location.
So far our timeline figures haven't reached into what is considered "early modern" history. I never realized that Columbus was making his discoveries in the middle ages. I love the having the chance to re-learn history. It's so fun!
We have the History Odyssey timeline (that I also laminated.) I adhere the cards to the timeline with velcro dots. You could use these cards on a homemade timeline just as easily of course. By the way, if you have a Mardel in your town, it has been the cheapest place I have found for lamination. It's only 25 cents a foot. I laminated all of my timelines for 3-4 bucks (along with a few other things.)
A few others asked for the files for the HOD timeline sheets I made as well. These enlarged sheets are better for you who have smaller children that have a more difficult writing small. I uploaded them to Google Docs for you here.
I still have more questions to answer that you folks asked, and as I have a minute here and there I will answer them. For now I hope these make fun additions to your homeschool day.