From almost the creation of the first true maps of the Earth, people started seeing how continents would be able to fit together. In particular, people noticed that South America fits almost exactly into Africa.
It is now known that most of the major continental masses can be fit together in a jigsaw process. In fact we now know that the continents were indeed once all joined together as one land mass the super continent of Pangaea.
If you look at most world maps you will ponder how this is evidence, as the continents really don’t appear to ‘fit’ together very well.