The Second Battle of the Marne was fought in the summer of 1918, just months before the end of World War I. It takes its name from the Marne, a river in France.
The battle was won thanks to an Allied counterattack led by French general Ferdinand Foch, the Supreme Commander of the Allied Armies. Foch later launched the Hundred Days Offensive, which led to the defeat of Germany.
The name Foch, which sounds like “foe” with an sh attached, was given to at least 58 U.S. baby boys in 1918. It was the 873rd most popular boy name in the nation that year, according to SSA data. (The SSDI includes people named Foch Pershing, Pershing Foch, and Victory Foch–all born in 1918.)
The name Marne was given to at least 24 baby girls and at least 17 baby boys in the U.S. in 1918. (Marne was the third-highest debut name for boys, in fact. First and second were Foch and Victory.) In France the river name is pronounced “mahrn” with a French R, but I doubt any Americans named for the battle used this pronunciation.