California Code
TITLE 3 - TRANSFER OF OBLIGATIONS
Section 1459.

1459. A non-negotiable written contract for the payment of money or personal property may be transferred by indorsement, in like manner with negotiable instruments. Such indorsement shall transfer all the rights of the assignor under the instrument to the assignee, subject to all equities and defenses existing in favor of the maker at the time of the indorsement.

(Enacted 1872.)