• 8. Wilson's Fourteen Points speech to joint session of Congress
  • 11. Wilson's Four Principles speech to joint session of Congress
  • 10. Captain James E. Miller assumes command of the 95th Aero Squadron
  • 16. Plant for assembly of American-made airplanes began operations at Romorantin, France. The 95th Aero Squadron departs Issoudun, France for the front.
  • 3. Soviet Russia and Central Powers make peace with Treaty of Brest-Litovsk
  • 5. The 95th Aero Squadron receives its first group of Nieuport N28 fighters
  • 9. Captain James Miller of the 95th Aero Squadron accepts the invitation of Major Davenport Johnson to join him and Major Harmon for a short patrol over the lines in three Spad VII fighters borrowed from a French squadron. The plane of Major Harmon had engine trouble and he had to turn back. Major Johnson and Captain Miller continued on and ran into four German fighters. Shortly after the fight began, Major Johnson abandoned the fight, leaving Captain Miller on his own. Captain Miller was shot down, and died from his injuries.
  • 12. Major Davenport Johnson assumes command of the 95th Aero Squadron
  • 15. The 95th Aero Squadron performs first patrol over lines in their Nieuport N28 fighters that havenít had the machine guns installed yet
  • 21. Ludendorff launches his series of major offensive assaults against the British , known as the "Kaiserschlacht" (Battle of Picardy) in an effort to gain a decisive victory before the effect of the America entering into the War can be fully realised. Major successes are reported.
  • 23. German offensive redirects towards Amiens and Paris. First American military balloon ascension in the AEF took place at Cuperly, Marne, France.
  • 26. Doullens Agreement gives General Foch "co-ordinating authority" over the western front
  • 27. First aircraft built at the Naval Aircraft Factory, the H-16 seaplane, was flown for the first time, and was later used for the antisubmarine patrol from United States and European stations.
  • 28. German Operation 'Mars' repulsed at Arras.
  • 4-5. Australians halt German advance at Villers Bretonneux.
  • 9. Germans launch 'Georgette' the second assault of their 1918 offensive (Battle of the Lys) in British sector of Armentieres.
  • 14. Foch appointed Commander-in-Chief of Allied forces on western front
  • 23. First oversea shipment of Liberty motors arrived at assembly and repair station at Pauillac, France.
  • 23-24. British attempt to blockade Ostend harbour fails.
  • 21. Germany's top ace of 80 victories, Manfred von Richtofen was killed in combat.
  • May
    • 11. First American-made DH-4, with Liberty engine, received in the AEF.
    • 16. Sedition Act; amendment to Espionage Act of 1917
    • 17. First flight made in France of an American-built military aircraft, a DH-4, built by Dayton Wright Co. adapted from English design.
    • 20. US Army Aeronautics was divorced from the Signal Corps and two air departments were created: Bureau of Military Aeronautics and Bureau of Aircraft Production.
    • 24. First consignment of American-built flying boats, six HS-1's, arrived at Pauillac, France.
    • 25 . German U-boats make their first appearance in US waters
    • 27. German offensive 'Blucher' launched. Third phase of 1918 German offensive (Third Battle of the Aisne) begins in French sector along Chemin des Dames
    • 28. 28th Regiment of US 1st Division goes into action at town of Cantigny
    • >29. German troops advance to the Marne but are stopped by US Divisions.
    • 3. 1st Lt. Sumner Sewall and two other 95th pilots engage six enemy fighters. The two other 95th pilots had to withdraw from the fight after their machine guns jammed. 1st Lt. Sewall engaged the six enemy fighters, shooting down one and allowing the other two US95th pilots to safely escape. 1st Lt. Sewall then made it back to his base after the engagement.
    • 6. 2nd Division captures Bouresches and southern part of Belleau Wood
    • 9. Opening of fourth phase of 1918 German offensive (Battle of the Matz) in French sector between Noyon and Montdider
    • 15-16. Austrian offensive at Asiago defeated by combined British and French force.
    • 27. Major David McKelvey Peterson assumes command of the 95th Aero Squadron from Major Davenport Johnson
    • 1. Standard Aircraft Corp. requested to build Italian Caproni and English Handley-Page bombers.
    • 2. Allied Supreme War Council supports intervention in Siberia
    • 6. Wilson agrees to American intervention in Siberia
    • 15. Ludendorff launches final phase of German offensive (Second Battle of the Marne)
    • 18. Allied counterattack seizes strategical initiative from Germans; nine US divisions participate
    • 3. Large-scale Allied intervention begins at Vladivostok
    • 8. Anglo-French counter-attack at Amiens supported by heavy artillery and 400 tanks achieves major successes. Ludendorff describes it as 'the Black Day' for the German army.
    • 10. 1st US Army organized under Pershing
    • 17. American-designed bomber, Army Martin MB-1, made its first flight with T. E. Springer as pilot. It became the first standard bomber of the Air Service but did not enter combat, while later modifications of it were used by the Post Office Department.
    • 4. American troops land at Archangel in North Russia
    • 12 . United States launches St. Mihiel offensive
    • 19. Opening of British offensive in Palestine (Battle of Megiddo)
    • 26. Meuse-Argonne offensive
    • 29. Bulgaria signs armistice
    • 12. American offensive at St Mihiel.
    • 23. British 15th Cavalry Brigade attacks Haifa.
    • 26. Allied offensive at Meuse-Argonne opens; greatest offensive of war for US forces
    • 1. First bombing using electrical releases, Allied bombers in an attack on German infantry counterattack.
    • 3-4. Germans and Austrians send notes to Wilson requesting an armistice
    • 12. Pershing forms 2nd Army under command of General Bullard
    • 21. Germany ceases unrestricted U-boat warfare
    • 26. Ludendorff is dismissed.
    • 28. Kiel mutiny by German sailors.
    • 1. Americans breakthrough German defences at Meuse.
    • 3. Mutiny of the German fleet, Soviets take control of Kiel.
    • 3. Americans cut vital Lille-Metz rail link.
    • 5. Congressional elections result in Republican control of Congress
    • 11. On the eleventh hour, of the eleventh day, of the eleventh month, the Armistice is signed effectively halting the War. The final Treaty of Versailles, is signed on June 28, 1919. With the signing of the Armistice, the US Army Air Service had a total of 195,024 personnel, of which 20,568 were officers, and the AEF had 3,538 airplanes while 4,865 were in service in the United States. Naval aviation consisted of 6,716 officers and 30,693 men, with 282 officers and 2,189 men in Marine Corps units with a total of 2,107 airplaines, of which 1,172 were flying boats.
    • 18. Wilson announces that he will attend peace conference personally
    • 13. Wilson aboard the liner George Washington arrives at Brest, France