“It was actually started to abolish slavery. It was the reason for its founding.”
The early Republican Party platform was to stop the expansion of slavery, not abolish it.
At least that is the way President Lincoln explained it.
The Democrat state of Georgia actually cast the decisive vote ratifying the 13th amendment.
Well sometimes you have to publicly understate your true goals. All of them were rather strong anti-slavery advocates. There true goal was to abolish slavery.. But realists know that you couldn't do it over night & you couldn't do it by being totally candid. There was already another party called the Free Soil party, who were all about prohibiting slavery in the western expansion territories of the country. So the Republican Party adopted their stance. The Free Soil party soon merged into the Republican Party.
So, you are technically correct, but they soon began advocating for the abolishment of slavery completely.