Melanie Kirkpatrick has this story in the WSJ on President Lincoln's 1863 proclamation and the magazine "editress" who led the campaign for the Thanksgiving holiday in its modern form.

Election Day has come and gone, and after one of the most divisive campaigns in memory, "healing" seems to be the word of the hour. What better time to begin than Thanksgiving, which Benjamin Franklin called a day of "public Felicity" to give thanks for our "full enjoyment of Liberty, civil and religious." Thanksgiving, our nation's oldest tradition, is a moment to focus on our blessings as Americans, on what unites us, not on what divides us.

Such was the case in 1863, when Abraham Lincoln called for a national Thanksgiving celebration. He did so at the urging of a farsighted magazine editor who believed that a Thanksgiving celebration would have a "deep moral influence" on the American character, helping to bring together the country, which was divided over the issue of slavery. Lincoln's 1863 proclamation was the first in the unbroken string of annual Thanksgiving proclamations by every subsequent president. It is regarded as the beginning of our modern Thanksgiving holiday.