Well I would not consider Adams landed gentry, but a New England farmer. You are really talking about the Virginians to include one of the the richest men in the country George Washington. Since you know your history you also know that this landed gentry was deep in debt and had what we would consider meager net worth, their heirs eventually having to sell their estates, .
All the more wonder that they created a Constitutional Republic that has evolved into one man one vote and was not established as a monarchy. If you recall a few asked Washington to become King and he refused going on to voluntarily step down from office after two terms. That was a unique event back in those times.This country was blessed in its leadership back then.