The Museums of Alma Mater are always full of surprises. This occasion marks the 200th anniversary of the U.S.A. diplomatic presence in Florence. Right after the unification of Italy, the University of Bologna stands out for its great interest in the Republic of North America. Giovanni Capellini, a young and brilliant geologist, realizes that the huge paleontological sites beyond the Atlantic Ocean constitute a great opportunity for research and for valorization. He knew that American scientists, with their incredible capacities, were already working in this direction, since the beginning of the 19th century. This is the reason why Capellini took a trip to the United States in 1863, marking the commencement of a solid relationship that culminated in 1909 with the donation of one of the casts of the Diplodocus carnegiei by Andrew Carnegie. An extraordinary story that is worth being told.