World War I also brought a tidal wave of social change, evident most immediately as many of the young men in society marched off to war. A disproportionately female population inhabited the home front everywhere, and this led to substantial changes in the work force. Most countries experienced a wave of unemployment followed by a surge in the need for labor. Young people, but especially women, entered the factories in large numbers. The world's most famous armaments plant, the Krupp works at Essen, Germany, employed 12,000 women in 1916; none had been employed there at the outbreak of the war. In the entire machine industry, women employees rose from some 75,000 before the war to nearly 500,000. In French munitions factories, women made up 25 to 30 percent of the work force by 1918. In France in 1914, and in Britain two years later, the government called on women to work as agricultural laborers. France's mobilization at the war's beginning drained the countryside of men at harvest time; the government asked farm women to step into the breach. In February 1916, the British government asked for 400,000 women to volunteer for work on the country's farms.