The IAAF ratified Charles Reidpath's 48.2 s performance set at that year's Stockholm Olympics as a world record, but it also recognized the superior mark over 440 yards (402.336 metres) run by Maxie Long in 1900 as a world record.
The "Time" column indicates the ratified mark; the "Auto" column indicates a fully automatic time that was also recorded in the event when hand-timed marks were used for official records, or which was the basis for the official mark, rounded to the 10th of a second, depending on the rules then in place.
From 1975, the IAAF accepted separate automatically electronically timed records for events up to 400 metres.
Starting January 1, 1977, the IAAF required fully automatic timing to the hundredth of a second for these events.
[1] Lee Evans' 1968 Olympic gold medal victory time of 43.86 was the fastest recorded result to that time.