Athens.
Marathon was a plain, not a tiny seaport town.
In 490 BC Greeks victoriously fought Persians in the Battle of Marathon in an attempt from King Darius I to subjugate Greece.
In 490BC when Pheidippedes, a Greek messenger, ran from the Battle of Marathon, to Athens to proclaim the Greek victory over the Persians
No, which is why they fought.
They were rallying calls for the Greeks. The Athenian success at Marathon demonstrated to the other Greek cities that the Persians could be beaten. Thermopylae became another symbol for Greek steadfastness which was used by the Greeks for propaganda on the superiority of the Greek warrior.
Herodotus.
The Battle of Marathon had shown to the Greek city-states that they could thwart Persian invasion forces and also proved that Greek armour and tactics were superior to those of the Persians .
Herodotus of Halicarnassus.
About 90,000 with 40,000 Greek allies on their side.
Marathon was not a war, it was one battle in a 50-year war between Persia and the Greek city-states. The most important battles were Salamis, Plataea and Mycale. The significance of Marathon is that it was the first time that the Persians were defeated, and this Athenian victory showed to the other Greek city states, after nine years of Persian victories, that the Persians could be beaten.
The Greeks stood their ground and fought for their freedom against the Persians. Their victory caused the Greeks many lives.
The Persians decided to bring all the Greek cities under control to enforce peace. They invaded in strength ten years later.
The battleground where the Athenians defeated the Persians. The messenger who was sent to deliver the message of victory, collapsed and died.