add some more context, this NYT editorial was written a couple days before Abraham Lincoln was sworn into office (March 4th, 1861).

The states had already voted to secede (or not to) earlier in the year. The Confederates had even provisionally elected a president, Jefferson Davis, on February 18th. The secession crisis started after Abraham Lincoln was elected in November of 1860.

The nation really was falling apart, hence the lamentation of the republic being just a collection of states in the editorial.