You're on Your Way, Teddy Roosevelt Book

Before Teddy Roosevelt became famous as a statesman, naturalist, colonel in the Spanish-American War, and twenty-sixth president of the United States, he was a young boy called Teedie who had wonderful adventures with his brother and sister and even started a museum in his attic. But he also struggled with terrible asthma. Overcoming his illness was the major battle of his young life . . . and his determination to make himself strong and healthy set the course for his amazing accomplishments to come.
First in a planned series of picture storybooks about "turning points" in the lives of the young Presidents, this book is written by the in-comparable author of So You Want to Be President? and whimsically illustrated by Matthew Faulkner.

As a young boy, "Teedie" Roosevelt was frequently ill, but worked hard to become strong and fit while also avidly reading and pursuing his love of natural history.