The Merci Train was a train of 49 French railroad box cars filled with tens of thousands of gifts of gratitude from at least that many individual French citizens. They were showing their appreciation for the more than 700 American box cars of relief goods sent to them by (primarily) individual Americans in 1948. The Merci Train arrived in New York harbor on February 3rd, 1949 and each of the 48 American states at that time received one of the gift-laden box cars. The 49th box car was shared by Washington D.C. and the Territory of Hawaii. Parades and ceremonies of welcome were conducted in the state capitols and major cities of almost all the states.
The 40/8 designation refers to the fact that during World War 1, each box car could handle either 40 soldiers or 8 horses as troops, horses and supplies were shipped to the front lines.
The symbol of the Merci Train to the right, shown next to the French flag, is a frontal view of a steam engine with flowers on the pilot which are symbolic of Flanders Field, where many American "Doughboys" from WW1 are buried. The drawing was adopted as the official symbol of the French Merci Train Committee, and a plaque of the drawing was placed on each of the Merci box cars. The committee also had gift tags made bearing the symbol, and one accompanied each of the more than 52,000 gifts that came in the box cars.