August Belmont faced significant criticism in the Northern states during the American Civil War due to his stance on promoting a negotiated peace with the South. His position was controversial as it conflicted with the prevailing sentiment among many northerners who were determined to defeat the Confederacy. Belmont's political actions, particularly his support for General George McClellan as the Democratic candidate in the 1864 presidential election, further fueled the backlash against him.

Belmont's advocacy for a peaceful resolution and his political affiliations placed him at odds with a majority of Northern leaders and citizens who favored a more aggressive approach to the conflict. This opposition highlights the deep divisions within the country during the war, revealing how differing opinions on peace strategies could affect individual political reputations and alliances during this tumultuous period.