Question: What Columbia President went to the university that hired the person who declared the American frontier "closed" in 1893?

<P0-S0> He was primarily known for his “Frontier Thesis.” He trained many PhDs who came to occupy prominent places in the history profession. <P0-S1> He promoted interdisciplinary and quantitative methods, often with a focus on the Midwest. <P0-S2> He is best known for his essay "The Significance of the Frontier in American History", whose ideas formed the Frontier Thesis. <P0-S3> He argued that the moving western frontier shaped American democracy and the American character from the colonial era until 1890. <P0-S4> He is also known for his theories of geographical sectionalism. <P0-S5> Frederick Jackson Turner (November 14, 1861 – March 14, 1932) was an American historian in the early 20th century, based at the University of Wisconsin until 1910, and then at Harvard. <P0-S6> In recent years historians and academics have argued strenuously over Turner's work; all agree that the Frontier Thesis has had an enormous impact on historical scholarship and the American soul. <SEP> <P1-S0> Politics: U.N. Secretary General Ban Ki-moon; American political leaders John Hancock, John Adams, John Quincy Adams, Rutherford B. Hayes, Theodore Roosevelt, Franklin D. Roosevelt, John F. Kennedy, Al Gore, George W. Bush and Barack Obama; Chilean President Sebastián Piñera; Colombian President Juan Manuel Santos; Costa Rican President José María Figueres; Mexican Presidents Felipe Calderón, Carlos Salinas de Gortari and Miguel de la Madrid; Mongolian President Tsakhiagiin Elbegdorj; Peruvian President Alejandro Toledo; Taiwanese President Ma Ying-jeou; Canadian Governor General David Lloyd Johnston; Indian Member of Parliament Jayant Sinha; Albanian Prime Minister Fan S. Noli; Canadian Prime Ministers Mackenzie King and Pierre Trudeau; Greek Prime Minister Antonis Samaras; Israeli Prime Minister Benjamin Netanyahu; former Pakistani Prime Minister Benazir Bhutto; U. S. Secretary of Housing and Urban Development Shaun Donovan; Canadian political leader Michael Ignatieff; Pakistani Members of Provincial Assembly Murtaza Bhutto and Sanam Bhutto; Bangladesh Minister of Finance Abul Maal Abdul Muhith; President of Puntland Abdiweli Mohamed Ali; U.S. <P1-S1> Ambassador to the European Union Anthony Luzzatto Gardner. <SEP> <P2-S0> ``the significance of the frontier in american history ''is a seminal essay by the american historian frederick jackson turner which advanced the frontier thesis of american history. <P2-S1> it was presented to a special meeting of the american historical association at the world's columbian exposition in chicago, illinois in 1893, and published later that year first in proceedings of the state historical society of wisconsin, then in the annual report of the american historical association. <P2-S2> it has been subsequently reprinted and anthologized many times, and was incorporated into turner's 1921 book, the frontier in american history, as chapter i. <SEP> <P3-S0> Several hundred thousand square miles (several hundred thousand square kilometers) of the Great Plains have fewer than 6 inhabitants per square mile (2.3 inhabitants per square kilometer)—the density standard Frederick Jackson Turner used to declare the American frontier "closed" in 1893. <P3-S1> The rural Plains have lost a third of their population since 1920. <P3-S2> Many have fewer than 2 inhabitants per square mile (0.77 inhabitants per square kilometer). <P3-S3> There are more than 6,000 ghost towns in the state of Kansas alone, according to Kansas historian Daniel Fitzgerald. <P3-S4> This problem is often exacerbated by the consolidation of farms and the difficulty of attracting modern industry to the region. <P3-S5> In addition, the smaller school-age population has forced the consolidation of school districts and the closure of high schools in some communities. <P3-S6> The continuing population loss has led some to suggest that the current use of the drier parts of the Great Plains is not sustainable, and there has been a proposal - the "Buffalo Commons" - to return approximately 139,000 square miles (360,000 km2) of these drier parts to native prairie land. <SEP> <P4-S0> the son of the well-known historian of the early american republic and editor of the "papers of alexander hamilton", harold syrett (d. 1984), david syrett was graduated from columbia university in 1961. after completing his m.a. <P4-S1> at columbia in 1964, he went on the university of london, where he completed his ph.d. in 1966 with a thesis on “shipping and the american war.