First problem, the spacious countryside did not have streets and most of the grand estates of the reclusive millionaires did not need street addresses. If you're a chauffeur or a butler or a gardener, you simply know the way up the winding country lane to the J.P. Morgan Estate or the MacKay Estate. By extension, most of the lesser millionaires followed the trend and gave names to their homes - not addresses.
Second, I am on the West Coast and cannot drop by the local county courthouse, library, university, and historical society where property records (not digitized) are kept. I could hire a researcher - and someday still might - to dig it up for me. I saw one advertising their services on a website, where they'll go beyond public records if they must and search vintage real estate listings and magazines.
What I've been able to find out (from 3,000 miles away) is this:
Old newspapers say that "The Box" was previously owned by Emily Ladenburg, who by the way, was a very cool gal. She was a millionaire's widow and instead of wearing black and crying behind lace curtains, she got out there and had a grand ol' time! She was one of the premier cross country riders, and broke fuddy duddy tradition by refusing to use a side saddle. She went on fox hunts.
Jack bought it shortly before he was killed. He went into debt renovating the place to his own style, and built a playground for his 4 year old son - complete with a see-saw, swings, and a slide. After his death, the mortgage went into default and the bank tried to collect from Blanca (even though they were divorced) - yeah, like she was going to pay a penny for it? A year later, the property went on the auction block and sold to Thomas Bowles of Kiowa, Kansas for $19,348. Again, this is from an old newspaper clipping.
However, I found a blog http://www.oldlongisland.com/2011/07/box.html that posted a real estate ad from a 1917 copy of Country Life magazine, where it calls The Box "A Bachelor's Country Home" for sale by Harvey Smith Ladew. The blog plots the location on Wikimapia as somewhere in Brookville, NY.
Thanks to Google Books, I found a digital copy of The Social Register from December 1914 that further confuses things. It lists Emily Ladenburg's home as "The Oasis" in Westbury, and Harvey Ladew's home is "The Box" in Brookville. Two different places.
Further confusing things is the tendency for things to get moved around, rebuilt, renovated, and renamed. The Meadow Brook Country Club, where Jack de Saulles tried to transfer his football and baseball skills to polo, closed down and then was resurrected.... in a different place. There's a town of Westbury... and Old Westbury which is nearer to Brookville. The Long Island Expressway (highway 495) covered up a lot.
Ultimately, for now all I have are the blurry newspaper photos from the sensational stories of the murder. The paparazzi swarmed around the place and took a bunch of snapshots. The District Attorney's office also had a professional photographer take shots of the crime scene, inside and outside, that were presented in court. Unfortunately, a fire in 1981 destroyed all of the Mineola court records and the original transcripts are lost.
