The following comes from:
TITLE I—ELECTRONIC RECORDS AND
SIGNATURES IN COMMERCE
SEC. 101. GENERAL RULE OF VALIDITY.
N GENERAL.—Notwithstanding any statute, regulation, or
other rule of law (other than this title and title II), with respect
to any transaction in or affecting interstate or foreign commerce—
(1) a signature, contract, or other record relating to such
transaction may not be denied legal effect, validity, or enforceability
solely because it is in electronic form; and
(2) a contract relating to such transaction may not be
denied legal effect, validity, or enforceability solely because
an electronic signature or electronic record was used in its
Of course this is a law written by lawyers so it can not be as simple as these two paragraphs in fact there are a total of 13 pages you can find here.