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.
If the new promise is to do something further than the promisor had already agreed to do, such promise is a consideration for a reciprocal promise. Thus where A was bound not to allow others to use his name in business.
12 Alabama. Stoudenmeier v. Williamson, 29 Ala. 558; Thomas on v. Dill, 30 Ala. 444; Warren v. Cash, 143 Ala. 158, 39 So. 124; Wellden v. Witt, 145 Ala. 605, 40 So. 126; Elliott v. Howison, 146 Ala. 568, 40 So. 1018.
District of Columbia. Hughes v. Brennan Construction Co., 24 D. C. App. 90.
Georgia. Crutchfield v. Dailey, 98 Ga, 462, 25 S. E. 526.
Iowa. Raymond v. Krauskopf, 87 la. 602, 54 N. W. 432.
Massachusetts. Munroe v. Perkins, 26 Mass. (9 Pick.) 298, 20 Am. Dec.
475; Rogers v. Rogers, 139 Mass. 440, 1 N. E. 122.
Michigan. Blagborne v. Hunger, 101 Mich. 375, 59 N. W. 657.
Pennsylvania. Spangler v. Springer, 22 Pa. St. 454.
Wisconsin. Snell v. Bray, 56 Wis. 156, 14 N. W. 14.
13 Raymond v. Krauskopf, 87 la. 602, 54 N. W. 432.
14 Shook v. Sachs, 121 Ark. 342, 181 S. W. 141.
15 Hughes v. Brennan Construction Co., 24 D. C. App. 90.
16 See Sec. 589 et seq.
a further promise not to engage in business himself is a consideration;1 and so when a surety consents to an extension of time.2 Where no time is fixed for the continuance of the contract, and it is held revocable at will,3 a promise of additional compensation for further performance is upon consideration.4 A substantial change in the form of a pre-existing liability is a consideration, such as a novation;5 the exchange of an absolute unliquidated liability for a contingent liquidated liability;6 an agreement by tenants in common to accept part of the entire estate in severalty and pay a proportionate share of a mortgage on the tract;7 or giving several small notes, providing for payment of attorney fees in case of suit, for one larger note involving no such provision.8 Payment of one-half a judgment by one of several judgment debtors in cash and notes secured by collateral, is consideration for a satisfaction of the judgment as to such debtor.9 If X, a third person, gives his note to A, a surety for B to C, in consideration of A's paying B's debt to C, a consideration for X's note exists, since A, while legally liable to C for such debt, had a right to await suit by C, and in that suit to compel B to pay the debt to the extent of B's property before A's property could be taken.10