Documentary on the subject (in French). Basically, two French officers where sent to North America to get 400 sled dogs before the 1915 winter to help with troop evacuation in the Vosges. Footage of this can be found here.
RB-36H Peacemaker of the 72nd Strategic Reconnaissance Squadron, Heavy (51-13741) flying over San Francisco Bay; ca.1954
The original concept was intended to bomb Germany from bases in North America because the US thought that Britain would fall to the Nazis. (Source)
A Convair B-36H sitting next to a B-29 Superfortress, for scale: