Feverfew is a small little town that lies directly across the waters from Starswirl's School for Gifted Unicorns, and is the most easily accessible point in going to and from the school. Students will find that ingredients, textbooks, and general school supplies are readily available in the town- after all, it makes for fantastic business.
Earth ponies founded Feverfew hundreds of years ago, back when the animosity between the pony races were still strong, and instances of cooperation were still far and few between. Named for the feverfew flowers that grew abundantly in the area, the town made excellent use of its natural resources to produce headache relieving teas and potions. For much of its early years, Feverfew enjoyed a life as a cozy little hamlet that produced these healing potions as it's main export, though under constant strain (for the most part) from the constant warring on an island off the coast near the village.
Families came and went, and for some time the earth pony Astera family came to dominate the island. Nopony knows which family first established the castle off the coast, but the Asteras inhabited it and brought a great deal of progress to the town. As magically gifted earth ponies- the Asteras pushed forward the innovation in potionmaking that so defined the little hamlet.
Eventually, the Requiems came to dominate the island- easily overtaking the Asteras. As magically gifted as the Asteras were, they were little match for the unicorn family who then lay claim to the island. Despite this sudden upheaval of power, the Requiems and the village still enjoyed well enough relations, especially as the town began to integrate into all three pony races. The trade routes established by the Requiems helped the town blossom.
Around the mid to late 1700s, the Requiem family ceased to be after each member of the family fell into madness. After all the Requiems had been purged from Feverfew, ponies avoided the castle out of fear until events were forgotten- and it became a ruin. With the ruin of the Requeims came the ruin of Feverfew, financial hardship hitting the ponies for the first time in years.
Celestia eventually purchased the castle, which brought a great deal of commerce and trade back to Feverfew- and a great helping of magic trade once more. Though the town now is able to stand on its own hooves without the assistance of magical trade, the boost that SSSfGU offered it can't be understated.
The coming of SSSfGU to Feverfew was both a blessing and a curse. Though it brought to Fevefew great wealth, it also brought great misfortune. The town became the target of an attack by the Apotheosis due to its relation to the school, surviving both a dragon assault and being invaded in 1865. A great deal of buildings have been burnt- but as always- Feverfew rebuilds. Needless to say, the relationship to the school is more that a bit tense, now.