I knew from the very beginning that my friendship with David was once-in-a-lifetime extraordinary and I treasured every minute of it. I wanted it to last forever but that ended up not happening. In South America, or at least in Chile, obituaries are not biographical but merely funeral notices so I'm going to try and write for David a North American-style obituary, with my comments/anecdotes in the footnotes.
David Marshall Billikopf, 91, passed away peacefully on March 25, 2018 at his home in Santiago, Chile, surrounded by family and others who cared about him. He was the son of the late Jacob and Ruth (Marshall) Billikopf , grandson of Louis Marshall, and nephew of wilderness activist Bob Marshall.
David was born on June 9, 1926, in Philadelphia, PA. He grew up in Philadelphia, spending summers in the Marshall family cottage at the Knollwood Club in the Upper Adirondacks of New York. He attended the Oak Lane Country Day School  and the Germantown Friends School  in Philadelphia before graduating with honors from Harvard University in 1947. He served in the United States Army from 1945 to 1946.
After college David hitchhiked across the United States and then sailed to Europe, spending a year traveling through France and Italy. 
In 1952 David married María Encina of San Javier, Chile.  During the 1950s and 1960s David played an integral role in managing the Encina family's vineyard. In 1955 David built a home for his family in the Las Condes section of Santiago, Chile. This home, where he passed away, is designated as a National Monument by the Chilean government.
In 1970, during a time of political turmoil in Chile, David brought his wife and five children to New Canaan, Connecticut, where they lived until returning to South America in 1975.  It was during this time that David wrote the book, "The Exercise of Judicial Power, 1789-1864," an extensive study of the beginnings of the U.S. Federal Court system and Supreme Court decisions during that period.
After returning to Chile David spent his years writing and traveling. He wrote several novels, novellas, short stories, and poems in both English and Spanish.
Besides his parents, David was preceded in death by his sister, Mrs. Florence Schweitzer, and a grandson, David Marsing Billikopf.
David is survived by three sons, Gregorio, Nicolás, and Yahia Billikopf; two daughters, Philippa Anderson and Stephanie Billikopf; 25 grandchildren, and 15 great-grandchidren (with two more on the way). He is also survived by his Godson, Monsignor Carlos Encina of the Vatican, as well as a host of family, friends, and caretakers.
 When David was ten years old his mother, Ruth Marshall Billikopf, died from breast cancer at the family's Knollwood cottage in the Adirondacks. Though it may have seemed to outsiders that David had everything a kid could want except for his mother, he never considered this to be the case. He said she was always with him, until the end of his life.
 The Oak Lane Country Day School was an experimental "Deweyite" educational preschool/elementary school where students were encouraged to follow their own instincts and learn at their own pace. Political philosopher Noam Chomsky also attended this school, a year behind David. In David's Second Grade progress reports (I read all of his progress reports from that school -- he called them his "Laundry Sheets") it was mentioned that although David was a brilliant student, he was "inclined to boss first graders," one of whom would have been Chomsky. I offered the theory that perhaps Noam Chomsky's strong anti-authoritarian leanings may have had their roots in being bossed around in the First Grade by young David B. Mr. Billikopf insisted that despite what it said in his "Laundry Sheets" he never bossed around any First Graders, so I let it go. I still think it's an amusing and very slightly plausible theory.
 Germantown Friends was a Quaker School and David was one of four Jewish students in a class of fifty. It was here that David was introduced to the New Testament of the Bible. At the end of his Tenth Grade year a term paper contest was held. David wrote about the history of the Catholic Church and his paper and the term paper of another Jewish student were chosen as the winners of the contest. David's prize was a copy of Bullfinch's Mythology. He never ceased to be amused that a Jewish kid at a Quaker school won a book about mythology for writing about the Catholic Church :)
 On September 20, 1949 David sailed to Europe on the SS Excalibur.
November 14, 1949 was a rainy night in the southern Italian region of Apulia and it was here on this night in the province of Foggia that David first experienced the Spirit of God, which was never to leave him. Though David descended from a thousand years of Rabbis he generally considered his form of Judaism as an ethnic identity more than a religion until the time of this experience in Italy. David and María Billikopf's children were raised in the Roman Catholic religion, and David himself embraced Catholicism though he considered himself a Theological Jew. Among his descendants today are Mormons, Muslims, Catholics, and other Christians. To my knowledge not a single descendant of David identifies theologically as Jewish.
 On December 31, 1950, David was sailing back to the United States on the SS Liberté when he received a cable informing him that his father had died that day in Philadelphia. It was at dinner on this same night that David met his future wife, María. He arrived in New York and made it to Philadelphia in time for his father's funeral on January 2, 1951. The next month he flew to Chile to see María and the courtship was on.
 The years David spent with his family in Connecticut were the only time he watched television. Living in Chile without a TV in the 1950s and '60s meant that he was completely unaware of the classic television shows that people my age and older either grew up watching or learned to love in syndication. That changed when he moved back to the States. His favorite TV shows were All in the Family, Sanford & Son, Hogan's Heroes, Get Smart, Monday Night Football, and Masterpiece Theater. Upon returning to Chile the television served only one purpose in his life until the end -- World Cup Soccer.
And there ends my footnoted obituary of the life of David Billikopf, a very brief summary with hundreds of interesting and amusing facts missing, along with one fact that is very much inconsequential -- that he was my friend, my sounding board, my trusted confidante. It mattered not to me how old or far away he was or how completely different our lives and families were. The fantastic stories and histories were simply footnotes of his personality and not the basis of my admiration for this person that I'll spend the rest of my life missing. Being able to drop French, Spanish, and Latin phrases in the same email, sometimes the same paragraph -- having someone who lived next door to Albert Einstein telling me that I'm intelligent -- calling me from 6000 miles away because he hadn't heard from me and was worried -- chauffeuring me around New York City to all the best spots in Manhattan via Wi-Fi -- putting EVERYTHING into a perspective steeped in wisdom like no other person I've ever known -- no, I'll never have a friend like that again. And I'll never stop missing David.