A "typo" by the founders in Article I, Section 10

According to our foundation, in Article I, Section 10, the following phrase appears:

executing it’s inspection Laws

This seemed like a typo to me. Shouldn’t it be “its” instead of “it’s”? So I dug it up in the national archives, and sure enough, it seems the founders used “it’s”. Might be an ink blot, but the official transcription has it too.

It seems more likely that the proper usage has just changed over time, but interesting nonetheless!