Urban planners at the end of the 19 century faced a "vexing" problem, writes Jill Jonnes: "how to connect the wealthy and influential island of Manhattan to the mainland and the rest of America." In Conquering Gotham, Jonnes chronicles the effort to make this connection, at least architecturally, with the construction of Pennsylvania Station and its tunnels. Jonnes ably recounts the technical challenges posed by a pioneering venture of such proportions, offering a refresher course in New York history along the way. But at its heart the book is an admiring biography of the "cultured, steely engineer" behind the plan: Alexander Cassatt (brother of artist Mary), whose efforts were stymied by politics, real estate battles, the limits of engineering -- and the fact that he was not from New York.