Answer:
If Patrick Henry had attended to the Constitutional Convention in 1787, there would have been an issue for its ratification as he was afraid of having a strong federal government. Taking this into acount, he would have made strong opposition to the Constitution, thus, causing a setback to reach an eventual consensus.
Wrapping-up, if all the Founding Fathers had attended, probably the ratification of the Constitution may have been delayed or even compromised.
Explanation: