The answer to the crossword is CARO, which is the surname of the author Robert Caro. Robert Caro is an American journalist and biographer who is best known for his Pulitzer Prize-winning book The Power Broker: Robert Moses and the Fall of New York. The book is a biography of Robert Moses, a public official who was responsible for much of the development of New York City in the 20th century. Caro's book is considered one of the most influential works of urban history ever written.