James R. McManus, the last of the long-reigning leaders of a Tammany Hall Democratic dynasty that presided over Manhattan’s politically tempestuous West Side since 1892, died on Monday at his home in the heart of it, Hell’s Kitchen. He was 84. The McManus family’s dominion was inaugurated by James’s great-uncle Thomas J. McManus, who was universally known as “The McManus,” to distinguish him as undisputed leader of the clan. In 1905 he deposed the West Side district leader George Washington Plunkitt. Like his father, grandfather and great-uncle, Jim McManus was an elected district leader, a relatively minor functionary in the great scheme of political office but a major neighborhood figure in the days when the clubhouses were cogs of well-greased machine politics. In a Midtown neighborhood (also called Clinton) west of the Theater District, where younger white collar workers were supplanting Irish dockworkers, Mr. McManus proved himself remarkably durable. Unlike most fellow district leaders, Mr. McManus sustained a robust, full-service neighborhood clubhouse (and a funeral home) in the West 40s, just west of Eighth Avenue. James Robert McManus was born in Manhattan on Sept. 10, 1934, to Eugene and Helen (Kearney) McManus. His father was a deputy chief court clerk. Jim grew up at 452 West 49th Street, near 10th Avenue. It was the same house that his great-uncle Thomas occupied until his death in 1926. After graduating from Power Memorial Academy in Manhattan and Iona College in New Rochelle, N.Y., Mr. McManus worked in the Times’s production department and, like his father, as a part-time funeral director. In 1965 he was named an assistant administrator for the city’s Board of Elections, which he described as a part-time rather than a no-show job. Mr. McManus never wed. His sister Maureen McManus was married to Michael J. Spillane, a bookmaker, loan shark and, by all accounts, gentleman gangster who was known as Mickey. He was murdered in 1977, and his gang was succeeded by a more brutal one, the Westies. In recent years Jim McManus’s nephew Michael J. Spillane Jr. (a restaurateur who is also known as Mickey) and niece Denise Spillane briefly inherited the leadership from their uncle. They were ousted in a Democratic primary in 2017. His nephew Thomas McManus is now the president of the McManus Midtown Democratic Association, as the West Side organization is known.