Kammala jumla mai zuwa: 3rd Battalion, 5th Marines, tare da sauran 5th Marine Regiment, an fara shirya shi ne a ranar 8 ga Yuni, 1917, yayin da Amurka ta shirya don yakin duniya na farko. Battalion ya kunshi kamfanoni hudu: "16th", "20th", "45th" da "47th". Kwana shida bayan haka, da sojoji na Spanish-American War da Boxer Rebellion tare da adadi mai yawa na sabbin ma'aikata, sun tashi zuwa Faransa. Sun halarci kamfen da yaƙe-yaƙe kamar
Bois de Belleau, Vierzy, Château-Thierry, Pont-a-Mousson, Limey Sector, Fleury, Meuse-Argonne, Blanc Mont, St Michiel, Leffincourt da kuma Soissons. Gwamnatin Faransa ta amince da matashin bataliya ta hanyar gabatar da ita Croix de guerre tare da Fourragère da kuma canza sunan wata alama ta Faransa, Belleau Wood, zuwa "Bois de la Brigade de Marine" ko "Wood of the Marine Brigade".