Thomas Jefferson was wild about numbers. He was constantly counting, measuring, and observing things that caught his interest. He loved sharing his discoveries and reading the discoveries of others. But when a famous Frenchman published a book about America, Jefferson was appalled: all the information in the book was wrong. The author insisted that America was a wretched, dismal place, where birds could not sing, dogs could not bark, and everything and everyone was puny and weak. Thomas Jefferson resolved to set the record straight—with numbers—and prove to the world that the new nation was worthy of investment. But how do you show that a country is plentiful in an age when photography hasn’t been invented yet?

Mara Rockliff, master of children’s nonfiction, details another little-known moment in math and natural history.