Dodgers and Giants in California 58 years.

If you consider 1901 the start of modern baseball, the Brooklyn Dodgers and New York Giants played 57 of those years in New York City.  Since 1958 they have played in Los Angeles and San Francisco respectively.  That's 58 years.

New York 3 team attendance 1920-1957 ... and comparison to California. Friday, June 20, 2014

Could New York support a third team? New York attendance v. others 1903-2013. Sunday, June 22, 2014

The apartment building in Brooklyn that replaced the home of the Brooklyn Dodgers. April 2015 by Saundi Wilson via Wikimedia Commons

Looking southeast at Polo Grounds Towers Housing Complex from Coogan's Bluff in Manhattan, New York City, on a sunny morning. March 2009 by Americasroof via Wikimedia Commons