Legal Definition of vested. 1  1 : fully and absolutely established as a right, benefit, or privilege : not dependent on any contingency or condition; specifically : not subject to forfeiture if employment terminates before retirement vested pension benefits. 2  2 : having a vested interest a vested employee a vested beneficiary.
Thomas Jefferson was the President when the Louisiana Purchase  transaction was negotiated. The people who actually signed the  Purchase Treaty were James Monroe, Robert Liv â¦ ingston, and Barbe  Marbois.
[edit] Negotiation. Jefferson laid the groundwork for the purchase by sending Livingston to Paris in 1801, after discovering the transfer of Louisiana from Spain to France. Livingston was to pursue a purchase of New Orleans, but he was rebuffed by the French. In 1802, Pierre Samuel du Pont de Nemours was enlisted to help negotiate.