Everything about this wonderful dive into Robert Caro’s extensive collection of notes and writing, and the plan for making them accessible via the New-York Historical Society, just feels so New York.

Mr. Caro grew up on Central Park West, between 93rd Street and 94th Street. His mother, Cele, learned she had cancer when he was 5 and died when he was 11. On many Saturdays, her sister, his Aunt Bea, would take the boy to lose himself in either the American Museum of Natural History or the New-York Historical Society.

Fast-forward to 2018. Mr. Caro realized that he would have to deal someday with his extensive archives; a few libraries had already inquired. “But my head was always in my book,” he said.

In his heart, though, Mr. Caro knew where he wanted his papers to go: the same historical society building where he found distraction as a boy, a beloved aunt by his side. He asked a friend to inquire whether there was interest. There most emphatically was.