Apocrypal Story of Pheidippides, the summary and timeline:
490 BC September Athenian army, outnumbered 5:1, defeat Persian army at Marathon.
484 BC Herdotus is born (died 424 BC), would write 'Histories' the authoritative account of the battle of Marathon.
The Athenian generals sent Philippides, a professional runner, to Sparta to ask the Spartans to help fight the Persian army, who had arrived by ship at Marathon. Philippides completed the 145 mile journey and arrived in Sparta the day after he left Athens. He delivered the Generals' request, then returned to Athens with the Spartan's reply - which was that due to observances they could not leave Sparta until the full moon. Upon receiving this news the generals decided to attack the Persians anyway, the result being an Athenian victory against seemingly overwhelming odds.
Having been beaten in the field, the Persians returned to their ships and set sail for Athens - to attack and ransack it while undefended. However, the Athenians marched the 25 miles overland and succeeded in reaching Athens before the ships, at which the Persians thought better of their plan and beat a retreat by sea.
Note that there is no mention in 'Histories' of a messenger being sent to Athens after the Battle.
300 BC Pontikos said that Thersippus a soldier made the trek from Marathon in full armor and collapsed. Truth be told, the entire Athenian army hurried back as the Persians jumped back on their ships and sailed to Athens. When they saw that the city was defended, the Persians conceded defeat.
600 years after the Battle of Marathon:
100 AD Plutarch wrote in 'Moralia' that Eukles made the 25 mile run from Marathon to Athens.
150 AD Finally, satirist Lucianus (basically the Dave Barry of the day) says that Pheidippides made the run from Athens to Marathon. After reaching the city, he said, "Rejoice, we conquer," and then collapsed and died