In what century did Labor Day become an official holiday in the United States?

Labor Day became an official holiday in the United States in the 19th Century. Specifically, it was established to honor and recognize the contributions and achievements of American workers amid the labor movement, which sought better working conditions, wages, and hours during a time of significant industrialization. The first Labor Day celebration took place in New York City on September 5, 1882, and it gradually grew in popularity across various states. Its official recognition came when President Grover Cleveland signed a bill making it a national holiday in 1894. This historical context highlights the importance of the 19th Century as the era during which labor rights began to gain significant national attention, solidifying Labor Day's role in American culture.