Clarence H. Mackay Family Correspondence

Identifier: 2015-19

Scope and Contents

The Clarence H. Mackay Family Correspondence contains letters to and from Mackay family members, Clarence H. Mackay, his wife Katherine Duer, and their children Katherine, Ellin, and John William III. Correspondence mostly dates from 1914-1924. A majority of the letters are from Katherine to her father, Clarence. There is also significant correspondence to Katherine from several individuals, including Fritz R. Caudert, Jr., and her mother Katherine.

In addition to the correspondence, the collection also includes a few miscellaneous pieces of correspondence, Robert Z. Hawkins' state bar certificates for Nevada and California, and a copy of The Illustrated Love Magazine with an article about Ellin and Irving Berlin.


  • 1870-1939


Conditions Governing Access

Collection is open for research. Materials must be used on-site; advance notice suggested. Access to parts of this collection may be restricted under provisions of state or federal law.

Historical Note

John William Mackay was born in Dublin, Ireland in 1831 to a working-class family. They immigrated to the United States when Mackay was nine years old, settling in New York City. In 1851, Mackay sailed to California in the search of gold. In 1859, that search took him to Virginia City, Nevada, where he became known as one of the Bonanza Kings, a group of four men who struck one of the largest silver lodes ever found.

In 1866, Mackay married Marie Louise Bryant Hungerford. They had two children: John William, Jr. (1870), and Clarence Hungerford (1874-1948). Although the family's fortune was made in Nevada, the family spent nearly all their time in San Francisco and New York.

As successful as his father, Clarence Hungerford Mackay made his fortune as the chairman of the board of the Postal Telegraph and Cable Corporation and president of the Mackay Radio and Telegraph Company. He married Katherine Duer (1878–1930) in New York on May 17, 1898. They had three children: Katherine (1900-1971), Ellin (1903-1988), and John William III (1907-1988). Katherine and Clarence divorced in 1910. Katherine Duer remarried in Paris, changing her name to Blake, but was divorced in 1914.

Katherine and Clarence's children grew up in New York and attended school there. Katherine married Kenneth O'Brien (1895-1954) in 1922, though their marriage ended in divorce. In 1938, she married Robert Ziemer Hawkins (1903-1979). Ellin, an accomplished author, married composer Irving Berlin (1888-1989) in 1926. Son John married Josephine Gwendolyn Rose (1908-2004) in 1929.


0.75 Linear Feet (2 boxes)

Language of Materials



The Mackay family includes Clarence Hungerford Mackay, son of John William Mackay of the Bonanza Kings fame, his wife Katherine Duer, and their children Katherine, Ellin, and John William III. The collection includes correspondence primarily between Katherine Mackay and her parents, family, and friends.


Arranged by recipient.

Immediate Source of Acquisition

Donated by Trent R. Dunphy in June 2015.



Guide to the Clarence H. Mackay Family Correspondence
Jessica Maddox
December 2019
Description rules
Describing Archives: A Content Standard
Language of description
Script of description

Repository Details

Part of the University of Nevada, Reno. Special Collections Department Repository

Mathewson-IGT Knowledge Center
1664 N. Virginia St.
Reno Nevada 89557-0322 USA
775-682-5724 (Fax)