in Washington, D.C. In 1861 he published his survey findings, entitled Notes on the State of Sonora. Civil War At the outbreak of secession, Stone found himself in Washington writing his report on Sonora. After a dinner with his former commander Winfield Scott, Stone was requested to be Inspector General of the District of Columbia Militia at the rank of colonel as of January 1, 1861, and was thus reputed to be the first volunteer officer mustered into the Union Army before the Civil War. In this role, he secured the capital for the arrival of President-elect Abraham Lincoln, and was personally responsible for security at the new president's inaugural. One of his most important acts in this role was to frustrate an attempt by southern militias and the secret society known as the Knights of the Golden Circle to carry out a coup against the nascent Lincoln administration. Stone received word that militia groups from Baltimore and surrounding areas intended to infiltrate Washington, D.C., and seize the city by force during Lincoln's inauguration. He dealt with two Milita officers (whom he knew to be succesionists) promply: First Stone maneuvered one commander ("Doctor B---" of the "National Volunteers Company") into handing Stone a full 100 men roster of his 300 men company to receive a order for arms; Stone accepted the roster and locked it into a desk drawer and wished the commander good morning; in turn the commander left his Washington D.C. home to give service to the Confederacy-his organization Broke up; the second officer ("Captain Schaeffer" of the "National Rifles" company ) was forced by Stone to give up two howitzers; as well as sabers and revolvers to the D.C. Armory on the grounds such weapons did not belong to a rifle company. Stone next offer to the man was a commission of Major. The man declined to take the Oath of Office and then found out he had lost his commission of captain as well since he had not inclosed a copy of the Oath of Office with his letter of acceptence. Schaeffer and the secession members left the "National rifles" Company which was transformed by Stone into a loyal Union company under Lt (elected Captain) Smead.Stone's prompt actions disintegrated the plot against the inaugural. Stone was appointed Colonel of the 14th U.S. Infantry Regiment on May 14, and then a brigadier general in the Union Army