I’d say no; everything had a reason at the time.
The only mistake that was made as I see it was not crushing the American communist insurgency in it’s infancy before letting them morph into the democrat party of today.
If they’d been stomped into the dirt where they belong several decades ago, we wouldn’t be on the verge of CWII right now.
Woulda, coulda, shoulda.
I agree with NFHale that no mistakes were made at the time. One mistake in the Constitution, however, was only providing a way for states to enter the Union. A way should have also be provided for them to be kicked out if certain standards were not met. Not upholding the Bill of Rights should grounds for removal, such as infringing free speech, religion, or firearms ownership, for example. Most progressive states would be cut loose by now.
Hear here!