Here's the meaning and also since September 11, 2001 we have also included a remembrance of those who perished on this day as well as all Military, Police, Fire & other safety personnel.
In the United States, Labor Day, the first Monday in September, is a creation of the labor movement and is dedicated to the social and economic achievements of American workers. It constitutes a yearly national tribute to the contributions workers have made to the strength, prosperity, and well-being of their country.
In many countries, the working classes sought to make May Day an official holiday, and their efforts largely succeeded. In the United States and Canada, however, the official holiday for workers is Labor Day in September. This day was promoted by the Central Labor Union and the Knights of Labor, who organized the first parade in New York City. After the Haymarket Massacre, US President Grover Cleveland feared that commemorating Labor Day on May 1 could become an opportunity to commemorate the affair. Thus, in 1887, it was established as an official holiday in September to support the Labor Day that the Knights favored.[1]