William James Young was born in 1800.   In 1813, with the consent of his father, he was indentured as an apprentice to instrument maker Thomas Whitney of Philadelphia for a period of seven years.  William J. Young was first listed in the Philadelphia, Pennsylvania directory in the year 1825 as a mathematical instrument maker.  He continued in business for himself until 1867 when Thomas N. Watson and Charles S. Heller joined him and the firm became known as William J. Young & Co., this arrangement lasted until 1870.    He died in Philadelphia in 1870.

Reference:   Smart, Charles E.  The Makers Of Surveying Instruments In America Since 1700   Troy, New York:  Regal Art Press.   1962