Why US does not celebrate Labor day on May 1?

Labor Day is a widely observed public holiday in which families and friends celebrate by gathering and enjoying picnics and outings.

This day has deep-rooted historical meaning from the 19th century in which the laborers of that day struggled to acquire rights for better working conditions and fewer working hours. 

Labor Day is celebrated on May 1 to honor the people who were part of the organised labor movement around the world meanwhile, it is celebrated as the first Monday of September citing historical significance in the US.

How did Labor Day start?

Labor Day was initially celebrated as an unofficial event by activists and some states in the late 19th century. Oregon was the first state to have enacted Labor Day into its law in 1887.

However, New York was the first that put forth a bill for the recognition of Labor Day. Later on, Colorado, Massachusetts, New Jersey, and New York also did the same at the end of 1887.

In the US, Peter J. McGuire, who was a union leader and founder of the United Brotherhood of Carpenters is regarded as the person behind the concept of Labor Day.

On September 1882, 10,000 workers joined a parade in New York City.

In May 1886, a violent confrontation of socialist workers occurred with the Police which is called Haymarket Riot or Haymarket Massacre in Chicago. This became the symbol of workers' struggle for their rights. Eventually, May 1 was designated as International Workers' Day by the Second International in 1889.

It took no more than five years that struggle and growing resentment forced US President Grover Cleveland, to sign legislation to make Labor Day — that was already being held in some states on the first Monday of September.

As the socialist trade unions and workers were already marking May 1 as Labor Day, US President Grover Cleveland was uncomfortable with choosing the month of the Haymarket Riot as Labor Day so he chose the alternative day in September.

A labor historian and professor emeritus at the City University of New York, Joshua Freeman had told CNN that the holiday developed as unions were beginning to strengthen again after the 1870s recession.

In New York City, two events converged that contributed to the formation of Labor Day. First, the now-defunct Central Labor Union was formed as an "umbrella body" for unions across trades and ethnic groups. 

Additionally, the Knights of Labor, then the largest national labor convention, held a convention in the city, complete with a large parade. But the parade fell on a Tuesday at the start of September — and many workers were unable to attend, Freeman had noted.

The convention was a huge success, and unions around the country started holding their own labor celebrations at the start of September, usually on the first Monday of the month.

In 1894 Congress a law marking the first day of September as a legal holiday called Labor Day.