Event of Interest
Apr 8 Carl Friedrich Gauss, German mathematician, proves the quadratic reciprocity law (the ability to determine the solvability of any quadratic equation in modular arithmetic)

Carl Friedrich Gauss
- Apr 13 First elephant arrives in US from India
Victory in Battle
Apr 13 Battle of Millesimo, Italy: Napoleon's forces defeat allied armies of Austria and of the Kingdom of Sardinia-Piedmont.

Napoléon Bonaparte