Article: In 1948, Eisenhower became President of Columbia University, an Ivy League university in New York City. The assignment was described as not being a good fit in either direction. During that year Eisenhower's memoir, Crusade in Europe, was published. Critics regarded it as one of the finest U.S. military memoirs, and it was a major financial success as well. Eisenhower's profit on the book was substantially aided by an unprecedented ruling by the U.S. Department of the Treasury that Eisenhower was not a professional writer, but rather, marketing the lifetime asset of his experiences, and thus he only had to pay capital gains tax on his $635,000 advance instead of the much higher personal tax rate. This ruling saved Eisenhower about $400,000.

Now answer this question: What group of schools did Columbia University belong to?
Ivy League