Then why did EVERY STATE adopt English Common Law at independence? Do you seriously think that the several states and the United States as a whole invented a new legal system? We simply carried over our existing laws under the new independent state governments. The entire American legal system is based on English Common Law. English cases prior to 1776 are routinely cited in American legal decisions.
The entire reason the Patriots went to war in 1775 was over violations of their rights as Englishmen.
The only person full of excrement is you.
If I remember this right the exception is Louisiana which uses the “Napoleonic Code” as common law.