The initials synonymous with the Republican Party—“GOP”—stand for “grand old party.” As early as the 1870s, politicians and newspapers began to refer to the Republican Party as both the “grand old party” and the “gallant old party” to emphasize its role in preserving the Union during the Civil War.
The Republican Party of Minnesota, for instance, adopted a platform in 1874 that it said “guarantees that the grand old party that saved the country is still true to the principles that gave it birth.”
In spite of its nickname, though, the “grand old party” was only a mere teenager in the early 1870s since the Republican Party had been formed in 1854 by former Whig Party members to oppose the expansion of slavery into western territories.