Lost River is based on the true story of Anna Ella Carroll, an unrecognized heroine of the American Civil War. She was raised to know law and politics even though there were no female lawyers or politicians at the time. She became a lobbyist, a reporter, and helped start the American Party. When the Civil War began, she helped keep Maryland in the Union by presenting Abraham Lincoln with a legal brief setting forth his presidential powers. Impressed, Lincoln soon allowed her to be an unofficial member of his cabinet. When in St. Louis, Anna discovered the Tennessee River had limited Confederate fortifications. She devised the Tennessee River Plan and notified Lincoln of her idea, advocating U.S. Grant as the general to execute it. President Lincoln used the plan to help win the war. It was his intention to honor Anna after the war, but fate decided otherwise. There were hearings to make her a major general, but she never received recognition for her accomplishments.