This section is from the book "The Law Of Contracts", by William Herbert Page. Also available from Amazon: Commercial Contracts: A Practical Guide to Deals, Contracts, Agreements and Promises.
Alteration, as the term is generally used in contract law, is a change in the language of a written instrument after the execution thereof, which is made intentionally by one of the parties thereto without the consent of the other.1 Alteration in this sense must be distinguished from other changes in the wording of a written instrument which do not amount to an alteration and have none of its effects.2
1 Arkansas. Robertson v. Southwestern Co., 136 Ark. 417, 206 S. W. 755.
Georgia. Winkles v. Guenther, 98 Ga. 472, 25 S. E. 527.
Illinois. Ryan v. First National Bank of Springfield, 148 111. 349, 35 N. E. 1120.
Massachusetts. Church v. Fowle, 142 Mass. 12, 6 N. E. 764.