[1] Mayer was privately educated in Baltimore and traveled abroad as a youth, before beginning work for his uncle Frederick Koenig.

[3][4] Showing "uncommon aptitude for commercial life", as a later biographer wrote, Mayer was dispatched to the west coast of South America on a trading voyage of two years, before returning to Baltimore.

[4] Mayer served as president for seven years,[3] playing a key role in the construction of the Baltimore Belt Line.

[7][8] Mayer also succeeded in separating the railroad from partial political control by the City of Baltimore and the State of Maryland, convincing them to sell their stock in the company in 1890.

His benevolence is proverbial, and many are the benefits he quietly and unostentatiously confers.A member of Baltimore society, Mayer served on many charitable and educational boards and trusts, including those of Johns Hopkins University, the Western National Bank, and the Baltimore Steam Packet Company.