Most of the letters in this book were written by Theodore Roosevelt to his children during a period of more than twenty years. A few others are included which he wrote to friends or relatives about the children. He began to write to them in their early childhood, and continued to do so regularly till they reached maturity. Whenever he was separated from them, in the Spanish War, or on a hunting trip, or because they were at school, he sent them these messages of constant thought and love, for they were never for a moment out of his mind and heart. Long before they were able to read he sent them what they called "picture letters," with crude drawings of his own illustrations of the written text, drawings precisely adapted to the childish imagination and intelligence. That the little recipients cherished these delightful missives is shown by the tender care with which they preserved them from destruction. They are in good condition after many years of loving usage. A few of them are reproduced on these pages—written at different periods as each new child appeared in the household.