What were the dough boys?

Answer 1

'Doughboys' was the nickname given to the American Expeditionary Force that took part in the later years of World War One. Before this decisive US involvement the colloquialism had applied only to infantryman, but at some point between April 1917 and November 1918 the word expanded to include the whole American armed forces. The term was not used in a derogatory sense, and is present in the diaries and letters of US serviceman, as well as newspapers. The actual origin of the term 'Doughboy' is still debated within both US historical and military circles, but it dates back to at least the American-Mexican War of 1846-7; an excellent summary of the theories can be found here. However, when US serviceman returned to Europe en masse during the Second World War, the term doughboy had vanished: these soldiers were now GI's. You may be interested to note that 'doughboy' was also the nickname of an inanimate object, a form of flour based dumpling that partly developed into the doughnut, and was in use by the late eighteenth century.

My source (http://europeanhistory.about.com/library/bldyk9.htm)