On Monday, about 200 letters, books and other ephemera from the late mayor's home in Manhattan's Greenwich Village are going on the auction block, many grouped in different collections.
Doyle New York has estimated most of them will sell for between $200 and $500.
Koch, who led the city from 1978 to 1989 with a combination of determination, chutzpah and humor, died in February at age 88. The brash, opinionated Democrat was credited with helping to save the city from its 1970s economic crisis and leading it to financial rebirth.
Among the highlights is a 1992 letter from Ronald Reagan in which the president tells Koch he "never doubted communism would eventually fail."
British Prime Minister Margaret Thatcher, in a Dec. 9, 1991 letter to the Jewish politician, discussed anti-Semitism in Croatia and the state of affairs in Yugoslavia.
There also is a group of letters from U.S. vice presidents in which Al Gore calls Koch "a great friend" and Dan Quayle writes that "Our special relationship with Israel must be preserved."
Jacqueline Kennedy Onassis, in a thank you note from 1991, tells Koch: "Your love of life is contagious and you sent everyone home feeling a happiness and insouciance that does not happen every day in dear old New York City."
The sale also includes 48 letters from Cardinal John J. O'Connor written between 1990 and 1999. The two men had a special relationship and co-wrote "His Eminence and Hizzoner" in 1989. A signed copy of the book is included with the letters.
In one, O'Connor tells Koch "you are indeed a friend." He also tells Koch that since he served for 12 years as mayor of New York, "I will not do it any longer as the Archbishop of New York."
O'Connor died in 2000. He served as archbishop for 16 years.
It is the second installment of Koch material to go on the auction block. His furniture and artwork were sold at Doyle last week. Among the highlights was a set of six Frank Lloyd Wright-designed dining chairs that sold for more than $11,000.
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