Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The men's 400 metres was a track and field athletics event held as part of the Athletics at the 1904 Summer Olympics programme. It was the third time the event was held. 12 athletes from 3 nations participated. The competition was held on August 29, 1904. At the 1904 Summer Olympics, twenty-five athletics events were contested, all for men only. Multi-event competitions, the decathlon and triathlon, were introduced for the first time. The short steeplechase was lengthened slightly, from 2500 to 2590 metres, while the long steeplechase was eliminated. The 5000 metre team race was replaced with the 4 mile team race. A 56 pound weight throw was added. In all, the 25 events featured in 1904 were 2 more than were held in 1900.