The customary units measuring system is the system of measurements used in the United States. It originated in Great Britain and was brought to this country by the early colonists who settled here shortly after the British Parliament adopted official standards in 1592.
The system evolved over many years of Norman and Saxon interactions with French, German and ancient Roman measurement systems, trade with Eastern merchants, and incorporates random elements from a variety of sources. Some measurements originally depended on arbitrary or chance occurrences such as the weight of a barleycorn or the width of a man’s thumb.
Because the system originated in England, speakers sometimes mistakenly refer to it as the British or British Imperial system. Great Britain dramatically overhauled its system in 1824 and although much of the unit terminology remains, the measurements and amounts are significantly different.