The U.S. Army Field Artillery is comprised of all units that operate artillery pieces designed to be used in the field, that do not fire at aircraft by design, be they towed or self propelled. This definition includes howitzers and MLRS (Multiple Launch Rocket Systems).
The headquarters of the U.S. Army Field Artillery is Fort Sill, Oklahoma.
Field artillery is called the 'King of Battle' due to its claim (possibly fact) of having inflicted the most casualties in every conflict since its inception.
Members of the Field Artillery are referred to as 'Red Legs' because during the American Civil War (and perhaps previously) they were distinguished by red stripes down the pant legs of there uniforms.