Why is it called legionnaires' disease?

How did this disease come to be given the name legionnaires. Thanks :-)

It was named after the people that first came down with the disease, though probably not the first, at a legionnaire's convention in Philly in 1976. The bacteria was then named Legionella pneumophilia, or "lung loving". It causes a very nasty pneumonia.

The first identified cases were at an American Legion convention in Philadelphia, PA. The cause was never definitely found, but suspected to have been an air conditioning cooling tower on the roof. The disease adds digestive disorders to the usual flu symptoms. Some 20% of cases of certain serotypes can be fatal.

Because it came to light among people who attended a convention of the American Legion in Philadelphia in July, 1976.

Legionnaires' disease is a type of pneumonia. It was named after an outbreak of severe pneumonia which affected a meeting of the American Legion in 1976. It is an uncommon but serious disease.