in the earliest days of our country america's founding fathers believed a citizens militia could handle most of our military needs, but after hundreds of years of wars and conflicts we now maintain the most powerful professional armed forces in the world. but we never disbanded our official militia. since 1903 it has been organized as part of the u.s. army and can be called up by state governors and the president in times of crisis. it's a militia that has evolved from minutemen and muskets to pilots and supersonic fighter jets and has a name you probably know, the united states national guard. >> we're your neighbors, your school teachers. we come from all walks of life because we're motivated by patriotism and the desire to serve the country. >> i've come to arlington, virginia to talk to the guard's second in command, lieutenant general mark sassville. what are the different kinds of militias?