	MacCracken married Edith Constable in 1910. MacCracken's father-in-law, Frederick Augustus Constable, managed Arnold Constable & Company in New York, and he was the son of one of the store's original partners. MacCracken's daughter Louise married Robert Olmsted, a trustee of Vassar College and the namesake of the school's biological sciences building. His son Constable was a graduate of Harvard University and Columbia Law School.