Labor Day has been synonymous with the end of summer for many years. But, Labor Day has a deeper meaning. The day is dedicated to the workers of America, and, as the Department of Labor states, "it constitutes a yearly national tribute to the contributions workers have made to the strength, prosperity, and well-being of our country."
As for the history of Labor Day, again, the DoL writes:
In 1884 the first Monday in September was selected as the holiday, as originally proposed, and the Central Labor Union urged similar organizations in other cities to follow the example of New York and celebrate a "workingmen's holiday" on that date. The idea spread with the growth of labor organizations, and in 1885 Labor Day was celebrated in many industrial centers of the country.
No matter how humble the beginnings were, Labor Day is to celebrate each and every one of us that work our buttons off all year-long. And so, I wish you all a wonderful Labor Day!