Americans want their soldiers to vote. But often they can’t. Despite absentee balloting, military personnel deployed overseas often just cannot participate in elections. For most of U.S. history, military personnel have not been able to vote. State laws and constitutions often specifically restricted military personnel from participating in the franchise. Attitudes about voting soldiers started to change when the Civil War called large numbers of citizens for military service—but action was tempered by partisan politics. The Civil War was the first time the United States had large numbers of soldiers deployed during a presidential election. Politicians of both parties were convinced that the army would vote for the commander-in-chief, Abraham Lincoln, a Republican. As a result, most states with Republican governors and legislatures passed laws enabling soldiers to vote, while most states led by Democrats did not. Those voting soldiers probably helped Abraham Lincoln in Maryland and influenced a few local elections in various states.
Here was the problem: Then as now, voting was usually conducted in local precincts. The idea that someone not physically present in their home county could cast a ballot was essentially unheard of. Many believed that absentee ballots invited election fraud.
But two methods of getting the vote to deployed soldiers were tried. Most states adopted a form of proxy voting, much like absentee voting today. The soldier marked a provided ballot and simply mailed it back to his home county or precinct. A few states actually tried to conduct an election in the field. Election commissioners were appointed; they then held elections on the designated day in various army camps.
After the Civil War states let the soldier voting laws expire, disenfranchising the military.