[bushpilot1]

Jefferson the Virginian page 385..

“They will bring with them the principles of governments they leave, imbibed in their early youth; or if able to throw them off, it will be in exchange for an unbounded licentiousness, passing, as is usual, from one extreme to another.....In proportion to their numbers, they will share with us the legislation.

They will infuse into it their spirit, warp and bias its directions and render it a heterogeneous, incoherent distracted mass....

[sometime lurker]

First, your quote nowhere has what you originally posted "they will destroy everything which we have built. If you are trying to argue that Thomas Jefferson didn't want foreigners to become citizens, look some paragraphs down to

If they come of themselves, they are entitled to all the rights of citizenship: but I doubt the expediency of inviting them by extraordinary encouragements…

So he appears to be saying the US should not take extraordinary measures to encourage immigrants. He certainly was not saying that natural born citizenship was restricted to the descendents of the original citizens at the time of the Constitution.