Kurschat was born into a family of a poor school teacher and received no formal education until age 28.

After Rhesa's death in 1840, Kurschat became the leader of the Lithuanian language seminar at the university and held that position for more than forty years.

During the German revolutions of 1848–1849, Kurschat established a conservative Lithuanian weekly Keleivis (Traveler) and edited it until February 1880.

[2] In 1822, priest Meyer from Neukirch (now Timiryazevo [de]) hired Kurschat as an assistant and a tutor for his children.

[3] He later moved to teach in Heinrichswalde (now Slavsk) where he earned just 70 Prussian thalers a year and to Kalthof (now Rizhskoye).

As Kurschat was fluent in Lithuanian and a diligent student, he became assistant to Rhesa who was elderly and of increasingly poor health.

When Russian philologist Pyotr Preis [ru] arrived to Königsberg to learn Lithuanian, Rhesa recommended Kurschat as his teacher.

[3] After Rhesa's death in 1840, Kurschat, while still a student, became the leader of the Lithuanian language seminar and held that position for more than forty years.

Kurschat increased the number of weekly hours by adding a course on Lithuanian grammar and a reading of The Seasons by Kristijonas Donelaitis.

[2] Kurschat ran in the 1874 elections to the German Reichstag as a candidate of the Prussian Conservative Party but received only 147 votes out of 5,748.

He promoted Lutheran religious ideals and supported the German Empire and the Kings of Prussia while criticizing "democratic vomit" directed at them.

[3] Already in 1843, Kurschat published a booklet (Beiträge zur Kunde der littauischen Sprache) for the attendees of the Lithuanian language seminar.

It contained an alphabetical list of most common German prepositional phrases and their Lithuanian equivalents.

Kurschat was not familiar with Universitas lingvarum Litvaniae, which was published in 1737 and briefly discussed Lithuanian accentuation, and came to his conclusions independently.

Event though the dictionary was expensive (unbound copy sold for 27 German marks), Kurschat did not earn any money from the publication.

Words that Kurschat could not attest from personal experience were written in square brackets, a unique feature highly valued by modern researchers.

[2] In 1844, he translated and published a booklet about the harms of alcohol and promoting the temperance movement by the German pastor Johann Heinrich Böttcher [de].

Receiving funds from the Prussian government, Kurschat established weekly Keleivis (Traveler) in July 1849 and edited it until February 1880.

For some time, Kurschat corrected language of Nusidavimai apie evangelijos prasiplatinimą tarp žydų ir pagonių, a monthly Lithuanian periodical reporting mainly on Evangelical missions in Asia, Africa, and South America.