[3] Hemphill introduced a bill in 1824 which called for the usage of military personnel to conduct surveys and estimate costs for construction of roads and canals.

[5] During the Congressional debate about the Indian Removal Act, Hemphill was split between his support for President Andrew Jackson and his Quaker constituency's opposition to the law.

[7] In 1831, Hemphill's son, Alexander, entered into a business partnership with William Ellis Tucker for his porcelain factory in Philadelphia.

[8] He purchased the Historic Strawberry Mansion in Fairmount Park from Judge William Lewis in 1821 and used it as his summer home.

[9] He added the Greek Revival wings to the structure and was known to entertain John C. Calhoun from South Carolina and the Marquis de Lafayette from France.