sentences:  Waldo was educated at the Berkeley School and the Columbia University School of Mines before attending the United States Military Academy at West Point.Columbia University's alumni notes show that he was a member of the class of 1899, but it was unsure whether he graduated with the class or not.He joined the Seventeenth Infantry Regiment of the United States Army as a Second Lieutenant in 1899, after the United States had occupied the Philippine Islands in the Spanish–American War.In the course of nearly four years in the Philippines, he served under General Arthur MacArthur, Jr., was on the staff of General Leonard Wood during the Moro rebellion, and commanded a battalion of Philippine Scouts.