Letters: Lincoln was no third-party candidate

I read with interest the letter from Jane Kenny calling Abraham Lincoln a third-party candidate.

The Republican Party had been around for years as the National Republicans and as the Democrat-Republicans before they split. In the 1850s the Republican Party attracted many anti-slave Democrats and drew off many Whig leaders from slave states, effectively killing the Whig party.

The Democratic Party was the party of slavery, and Lincoln was elected the first Republican president in 1860. I do not believe it is accurate to call him a third-party candidate.