What caused the race to the sea?

The Race to the Sea was prompted by the stalemate on the Western Front during World War I, where both the Allies and Central Powers sought to outflank each other. After the failure of the Schlieffen Plan and the Battle of the Marne in 1914, both sides dug extensive trench systems, leading to a prolonged deadlock. As they attempted to gain strategic advantage, forces pushed northward towards the English Channel, resulting in a series of engagements that characterized this phase of the war. Ultimately, the Race to the Sea solidified the trench warfare that would define much of the conflict.