1903
1904
1906
1907
1908
1909
1910
1912
1914-18
1914
1915
1916
1918-19
1919, Aug
1920
1924
1925
1926
1927
1928
1929, Oct
1929-41
1930
1931
1932
1933
1935
1936
1937
1938, Nov
1939-40
1939-45
1943
1947
- - - Clarence named President of both Commercial Cable Company and Postal Telegraph-Cable Company. "Mackay-Bennett System" renamed "Mackay System"
Second daughter Ellin born to Clarence and Katherine
First Trans-Pacific cable completed by Pacific Commercial Cable Company
Katherine Mackay builds/dedicates Trinity Episcopal Church to her parents
Son, John W. Mackay, born to Clarence and Katherine
Clarence and Louise dedicate Mackay School of Mines and Statue of John W. Mackay at University of Nevada, Reno
Clarence striken by cancer, Dr. Blake operates and saves his life
- - - 25th Anniversary of Mackay System
Katherine leaves family and runs off with Dr. Blake
First award of Mackay Trophy goes to Lt. Hap Arnold
World War I
Clarence and Katherine divorced, children stay with Clarence
Clarence assists in founding of Canterbury School in Connecticut
Clarence takes 20 year lease on Gardiner's Island for hunting preserve
Federal government nationalizes cables, telegraph and radio
Control of Mackay Companies returned to Clarence
Clarence's mother, Louise, returns after 44 years in Europe upon death of Clarence's half-sister, Eva, and takes up residence at Harbor Hill
40th Anniversary of Mackay System
- - - Gala party at Harbor Hill for Prince of Wales. 1,200 guests
Clarence founds Mackay Radio Company. Integrates cables, telegraph, radio
Daughter Ellin elopes with Irving Berlin, Clarence disinherits her
Gala party at Harbor Hill for Charles Lindbergh after return from solo flight to Paris
Clarence sells Mackay Companies to ITT. "Mackay System" renamed "The International System".
- - - Louise dies peacefully at Harbor Hill (age 85)
Stock Market Crash
Great Depression
Ex-wife Katherine dies of cancer, freeing Clarence to remarry
Clarence marries long-time friend and Opera/Concert Singer, Anna Case
- - - Wedding at St. Mary's in Roslyn, reception at Harbor Hill
Sale of special Art, Armor and Tapestry to Metropolitan Museum of Art
Mansion at Harbor Hill closed, Mackays stay but move into Superintendent's house
Mackay finances improve, mansion reopened at Harbor Hill
- - - Postal Telegraph-Cable Company declares bankruptcy
Clarence's cancer returns
Clarence adds last items to arms collection (Pair of dueling pistols)
Clarence Mackay dies of cancer at his 75th Street, NYC mansion (age 64)
Germain Seligman disposes of Mackay Art, Armor and Tapestry collections
World War II
Postal Telegraph merged into Western Union
Clarence's son, John W. Mackay, has Harbor Hill mansion demolished to stop vandalism, lower property taxes and prepare grounds for future real estate development of "Country Estates"