Early 20th Century Photo of Mansion with American Flag - Ambassador's Residence?

This is an early 20th century photo of a mansion, with an American flag flying above it.  In the lower right corner there is a dog (looks suspiciously like a collie, but who knows), and there are trees and shrubbery around it.

Someone contacted me awhile back and had some good info about this building, but I have unfortunately lost  it.  The gist of it was that this was the old residence of the American Ambassador to Great Britain.

I can't date this precisely, but based on the mounting and type of photo (I believe it is gelatin silver), this is probably WWI era, give or take.

Photograph of a Man with a very large Dog

This is an antique photo of a man with a very large dog, I think a Great Dane.    It was photographed by Renshaw, of 2718 Girard Ave in Philadelphia.  Writing on the back indicates the man is named Louis Haeckner, and that he was born in Germany.

We've listed a lot of photos of the Hackner's (sometimes spelled Haeckner) recently.  Margaret Hackner, who I suppose was a daughter, married Oliver Phillips, and we have a lot of photos of that side of the family.

This is an early 20th century Gelatin Silver photograph, and there is heavy silvering on the photo, so heavy that if you tilt it slightly one way or another, the silvering is all you can see.  Tilt it slightly toward you and you see a sharp photograph.   I don't know the exact date of the photo, but it is probably 100 years old or close to it.

It is an unusual studio photo - a man with a huge dog in his lap - and the type that many people find interesting.   At least I do. 

Update:  Sold!

Another Update - the dog may be a Presa Canario, not sure.

Little Girl, Big Dog - Early 20th Century Postcard

For some reason people seem to like little girls with big dogs.  I can't blame them, I partial to the dogs, myself.  Just ask Pickles.

There is a whole series of these cards, and I have a couple of them.  Some of them have the same dog & girl, others are different.  But the background and scene are the same.

I've noticed that postcard publishers do that.  You'll see the exact same pictures in different formats sometimes.  Sometimes you'll see the same picture but with a different caption.  I think I have a postcard which somehow placed the Rocky Mountains in Kansas.  

This is a pretty postcard, early 20th century, divided back.  On the back the word "post card" is printed in about 20 different languages.

Not sure what kind of dog it is, but it's pretty good size.

Update:  Sold!