Throughout history, boundaries and borders have been redrawn. Knowing where those lines fell during the life of your ancestors is another key to finding your story!
Go to ancestry.com or ancestry.ca
Go to search (at top of screen along the panel of choices), search all records (drop down window), see more (at the bottome of the features section) and then you will have all the record collections in front of you.
"Maps, Atlases & Gazetteers" or see more for a complete library of maps (countries, years...)at the bottom of the title "Maps, Atlases & Gazetteers"
Ancestry Map Search Link
Good Luck on your findings.