Isaac Gale Johnson’s five sons — Isaac Mattison, Isaac Bradley, Gilbert Henry, Arthur Gale and James Wagner — entered the business in their youth after the plant was opened. These sons were to be known by their initials — I.B., I.M., and so on. In spite of the differences in age, all of the brothers got along harmoniously. They lived near each other on Spuyten Duyvil Hill. His spouse was Jane Eliza Bradley Johnson, BIRTH 22 Jul 1832 Sunderland, Bennington County, Vermont, Died 7 May 1906 (aged 73)Spuyten Duyvil, Bronx County, New York. It would appear that the steps were named for their mother’s maiden name “Bradley”