Enoch Pratt's first American ancestor on his father’s side arrived in Massachusetts in 1628; on his mother’s side, in 1662. When his formal education ended at the age of fifteen, he moved to Baltimore and began his business career by selling nails and mule shoes before moving into transportation, insurance, and banking. From 1860 until his death, he was the president of the National Farmers’ and Planters’ Bank of Baltimore. Pratt also became president of the Baltimore Clearing House and the Maryland Bankers’ Association, in addition to establishing a role in several transportation companies.

Enoch Pratt and his wife had no children. He dedicated his growing wealth to civic improvement in Baltimore. Indeed, he became a great philanthropist like two other Baltimore Unitarians: Johns Hopkins and George Peabody. After building a free central library and four branch libraries, he granted the city $833,333.31 to assure that the library which he gave the city would always be free to all. At the beginning of the twenty-first century, there are more than 25 branches of the Enoch Pratt Free Library. Andrew Carnegie was so impressed that he began libraries in other cities, declaring,”Pratt was my pioneer.”