Liberia or the Republic of Liberia was neutral for most of the war until Agust 4, 1917.
Before the war
Liberia was one of the only independent African countries other than Ethiopia. It had been established by a group of emancipated slaves from the United States who established a government and country in the 1840s. They tightened their grip over the indigenous black population, often enslaving them. From 1912 to 1920 the country was ruled by president Daniel Edward Howard, who had to deal with problems externally and internally. The finances of the state were so bad, government employees weren't paid for months at a time.
Outbreak of War
Liberia relied on French, British, and American trade, which soon became threatened by German U-Boats during the war. In 1917, Liberia joined the war with the allies and liquidated property of German nationals to pay off the coast the submarine blockade had on Liberia. The involvement of Liberia in the war was minimal, although, in 1918, a submarine shelled the capital of Monrovia. As an allied nation, Liberia received liberty loans from the United States, yet financial support greatly decreased after the war. The Liberian legislature signed the Treaty of Versailles but the next years after the war would be those of hardship.