This ancient name of Medieval Scottish origin is a locational surname from the lordship and manor of the same name in Lanarkshire, Scotland. The derivation is from the Old English pre 7th Century 'ceald', cold and 'wudu', a wood. The following examples illustrate the name development after 1296 (see below), John de Calderwode (1456 Register of Panmure), Edward de Caldorwud (Cambuslang 1458), Archibald Caldderwood (1509 Cadder). One David Calderwood (1575-1650) was born at Calkeith and the author of the History of the Kirk of Scotland. The Calderwood family were settled at Dalkeith from 1566 onwards and were numerous in the parish in the 17th Century. The name was introduced into America in 1725, when James Calderwood emigrated first to Londonderry, Ireland in 1724 and from there to New Hampshire, U.S.A. The first recorded spelling of the family name is shown to be that of Isabele de Calrewode, which was dated 1296, Lanarkshire, Scotland, Public Records Office, during the reign of John Balliol, 1292-1296. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.