Born into the Italian nobility in Milan, Castiglioni grew up under the tutelage of his uncle, Pietro Verri, after the death of his father.
[1] With his status and scholarly accolades behind him, Castiglioni entered the intellectual circles of the United States with ease: becoming acquainted with the likes of Benjamin Franklin, Thomas Jefferson, George Washington, and John Adams (among others).
Viaggio described the people, places, history, customs, and nature he encountered in the United States, and most notably suggested American plant life that could be beneficially introduced to the withering forests of northern Italy.
After the fall of Napoleon, Castiglioni went as a delegate to rally for continued Italian independence at the Allies meeting in Paris in 1814, to no success.
Austria now in control of his homeland, Castiglioni’s political career may have ended, but his accolades continued to pour in: he earned a knighthood in 1819, and membership to societies all over Europe.