The American Civil War was a grueling four years in American history, where there were over 600,000 casualties. What motivated these men to enlist at the start of the war, continue to endure the hardships of war, and take up arms against their own countrymen? According to historian John A. Lynn, these can be divided into three categories of soldier motivations: initial motivation, ongoing motivation, and combat motivation. Author James M. McPherson uses these categories as his thesis in his book “For Cause and Comrades” and proves it successfully. According to McPherson, the factors that initially motivated men to enlist in the army at the start of the war were duty, honor, and country. Each of these motivators are linked. He talks about many Union men writing letters to their loved ones explaining that it was their duty to enlist. “It is everyone's duty to enlist, if they can, and why is it not mine as much as that of others? If you are not willing to send your sons, why should others be willing to send theirs? (McPherson, 23). Duty is linked to both honor and country. A man will feel it is his duty to fight for the country in which he lives and whose government has protected him. The quote above, from a letter from a Harvard student to his father, also illustrates the idea of ​​preserving honor. When he talks about others going to war, there is a sense of honor that he must also go to war. He uses this idea to try to convince his father that his son should enlist. If this man didn't go to war, what about the other families who sent their son to war? Motivation through patriotism can be seen in Abraham Lincoln's inaugural address. “Lincoln had said in the middle of his diary...the next day” (McPherson, 41). Fighting illness wasn't the only thing adrenaline helped. Wounded men could continue to fight despite a surge of adrenaline. These chemical changes caused humans to ignore the fact that they were in danger and made them even more dangerous killers. It seems that, compared to what the author has written about initial and combat motivations, maintaining motivation has been somewhat neglected. McPherson cites many examples and many different factors that encouraged men to enlist and stay motivated in the midst of battle; however, he does not go into as much detail when talking about what motivated the men to stay in the war, aside from a few main points. Regardless, James M. McPherson proves his thesis in "For Cause and Comrades" by showing motivators divided into three main categories by historian John A. Lynn..