A U.S. Air Force C-17 Globemaster III sits on the flightline, Sept. 16, 2018, at Joint Base, Charleston, South Carolina. https://www.rawpixel.com/image/8727765/photo-image-airplane-public-domainFree Image from public domain licenseBattle of Belmont. Nov. 23D 1899. Boer-British War, Kurz & Allison. https://www.rawpixel.com/image/7688503/battle-belmont-nov-23d-1899-boer-british-war-kurz-allisonFree Image from public domain licenseU.S. Air Force Airman 1st Class Elijah Bishop, left, an intelligence analyst assigned to the 347th Operations Support… https://www.rawpixel.com/image/8741274/photo-image-art-public-domain-paintingFree Image from public domain licenseU.S. Air Force Pararescuemen with the 38th Rescue Squadron jump from the back of an HC-130J Combat King II aircraft over… https://www.rawpixel.com/image/8728480/photo-image-public-domain-person-manFree Image from public domain licenseA U.S. Air Force pilot assigned to the 75th Fighter Squadron taxis an A-10C Thunderbolt II toward the runway, Dec. 6, 2017… https://www.rawpixel.com/image/3318879/free-photo-image-pilot-amxs-wingFree Image from public domain licenseU.S. Air Force Airman 1st Class Zachary Rollins, an aircrew flight equipment technician with the 347th Operations Support… https://www.rawpixel.com/image/8741581/photo-image-public-domain-person-manFree Image from public domain licenseA U.S. Air Force HC-130J Combat King II assigned to the 71st Rescue Squadron taxis towards the parking ramp during Stealth… https://www.rawpixel.com/image/8728491/photo-image-airplane-public-domainFree Image from public domain licenseAirman 1st Class Daniel Ross, 822d Base Defense Squadron fireteam member, looks for signs of improvised explosive devices… https://www.rawpixel.com/image/8739325/photo-image-public-domain-person-natureFree Image from public domain licenseU.S. Air Force A-10 Thunderbolt II aircraft assigned to the 74th Fighter Squadron’s taxi July 11, 2017, at Moody Air Force… https://www.rawpixel.com/image/3318260/free-photo-image-wing-23d-9th-air-forceFree Image from public domain licenseShowing Cylinder and Rock Arbor. [North Adams Marble Co. Works, Near Natural Bridge, April 23d, 1873.] by William P Hurd https://www.rawpixel.com/image/14291487/photo-image-plant-person-woodFree Image from public domain licenseU.S. Air Force Senior Airman Nicholas Dacyk, a hydraulics systems apprentice assigned to the 723d Aircraft Maintenance… https://www.rawpixel.com/image/8739580/photo-image-public-domain-person-sunglassesFree Image from public domain licenseThe Seven Regiment in front of the Union Hotel, - - - Saratoga Springs, [N.Y.], July 23d, 1869. by Deloss Barnum https://www.rawpixel.com/image/14286629/photo-image-person-art-public-domainFree Image from public domain licensePontoon Bridges on North Anna, Below Railroad Bridge, Where a Portion of the 2nd Corps under Gen. Hancock, crossed 23d May… https://www.rawpixel.com/image/14297153/image-person-art-public-domainFree Image from public domain licenseSnow covers an HC-130J Combat King II on the flight line of Moody Air Force Base, Ga., Jan. 3, 2018. https://www.rawpixel.com/image/8728069/photo-image-airplane-public-domainFree Image from public domain licenseA coachman, a cook and a household servant in a state of intoxication refuse to open the door of their quarters to their… https://www.rawpixel.com/image/14010679/image-cartoon-face-personFree Image from public domain licensePontoon Bridges on North Anna, Below Railroad Bridge, Where a Portion of the 2nd Corps under Gen Hancock, Crossed 23d May… https://www.rawpixel.com/image/14310558/image-person-art-collageFree Image from public domain license