The establishment of the first federal holidays in the United States was a crucial legislative action aimed at creating a unified national identity through designated days of celebration and reflection. The holidays enacted were New Year's Day, Independence Day (July 4th), Thanksgiving Day, and Christmas Day—each selected for their significant cultural, historical, or religious connotations. Congress identified the importance of these days in American life and sought to formalize them into a cohesive structure recognized by federal law.

The decision arose in the context of a nation still redefining itself after the Civil War. As the United States sought to heal from the divisions of war and the challenges of Reconstruction, establishing common holidays served as a means of promoting national unity and pride. The 1870 federal holiday law marked a shift from the earlier, informal observance of holidays at the state and local levels to a more organized and federally recognized standard.

Series of debates in Congress highlighted the tensions between local practices and the desire for a more cohesive national approach. The inclusion of holidays like Thanksgiving, celebrated in various forms across the states, was particularly significant as it symbolized gratitude and reflection. Through this legislation, Congress codified important traditions and established a framework that would shape how Americans celebrate significant dates in their cultural heritage.