Section 2. Service referred to in section one shall mean service during any of the following periods, both dates inclusive: — (a) Mexican Border Service, between June nineteenth, nineteen hundred and sixteen and February third, nineteen hundred and seventeen, provided, that such service was in the Massachusetts National Guard; (b) Cuban Pacification Campaign, between October sixth, nineteen hundred and six and April first, nineteen hundred and nine; (c) Nicaraguan Campaign, between August twenty-eighth, nineteen hundred and twelve and October thirtieth, nineteen hundred and twenty-nine; (d) Vera Cruz Expedition, between April twenty-first, nineteen hundred and fourteen and November twenty-sixth, nineteen hundred and fourteen; (e) Dominican Campaigns, between May fourth, nineteen hundred and sixteen and September seventeenth, nineteen hundred and twenty-four; (f) Haitian Campaign, between July ninth, nineteen hundred and fourteen and October thirtieth, nineteen hundred and twenty-nine; (g) China Expeditionary Service, between October thirtieth, nineteen hundred and twenty-nine and June thirtieth, nineteen hundred and thirty; (h) Army of Occupation in Germany, also known as the A.E.F., between November twelfth, nineteen hundred and eighteen and July eleventh, nineteen hundred and twenty-three; provided, in any case, that proof of service in the campaign, army of occupation or expedition mentioned is made.