It was Sarah Josepha Hale that wrote to then President Abraham Lincoln, urging him to establish a dedicated national day of thanksgiving. She sent the letter on September 28, 1863. A digitized version of her letter is below, click here to read the transcribed text.

Lincoln does issue a Proclamation of Thanksgiving, officially establishing the national holiday for the first time. In the midst of the Civil War, Lincoln acknowledges the tragedy, but also attempts to find hope and blessings, and thanks. He writes, “I do therefore invite my fellow citizens in every part of the United States, and also those who are at sea and those who are sojourning in foreign lands, to set apart and observe the last Thursday of November next, as a day of Thanksgiving and Praise to our beneficent Father who dwelleth in the Heavens.” Read the entire proclamation here.

President Obama has issued a Thanksgiving Proclamation each of his years in office. The White House just released this year’s version. You can read it below:

THANKSGIVING DAY, 2013

– – – – – – –

BY THE PRESIDENT OF THE UNITED STATES OF AMERICA

A PROCLAMATION

Thanksgiving offers each of us the chance to count our many
blessings — the freedoms we enjoy, the time we spend with loved
ones, the brave men and women who defend our Nation at home
and abroad. This tradition reminds us that no matter what our
background or beliefs, no matter who we are or who we love, at
our core we are first and foremost Americans.

Our annual celebration has roots in centuries-old colonial
customs. When we gather around the table, we follow the example
of the Pilgrims and Wampanoags, who shared the fruits of a
successful harvest nearly 400 years ago. When we offer our
thanks, we mirror those who set aside a day of prayer. And when
we join with friends and neighbors to alleviate suffering and
make our communities whole, we honor the spirit of President
Abraham Lincoln, who called on his fellow citizens to “fervently
implore the interposition of the Almighty hand to heal the
wounds of the nation, and to restore it, as soon as may be
consistent with the Divine purposes, to the full enjoyment of
peace, harmony, tranquility, and union.”

Our country has always been home to Americans who recognize
the importance of giving back. Today, we honor all those
serving our Nation far from home. We also thank the first
responders and medical professionals who work through the
holiday to keep us safe, and we acknowledge the volunteers who
dedicate this day to those less fortunate.

This Thanksgiving Day, let us forge deeper connections with
our loved ones. Let us extend our gratitude and our compassion.
And let us lift each other up and recognize, in the oldest
spirit of this tradition, that we rise or fall as one Nation,
under God.

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NOW, THEREFORE, I, BARACK OBAMA, President of the
United States of America, by virtue of the authority vested in
me by the Constitution and the laws of the United States, do
hereby proclaim Thursday, November 28, 2013, as a National Day
of Thanksgiving. I encourage the people of the United States
to join together — whether in our homes, places of worship,
community centers, or any place of fellowship for friends and
neighbors — and give thanks for all we have received in the
past year, express appreciation to those whose lives enrich our
own, and share our bounty with others.

IN WITNESS WHEREOF, I have hereunto set my hand this
twenty-sixth day of November, in the year of our Lord
two thousand thirteen, and of the Independence of the
United States of America the two hundred and thirty-eighth.

BARACK OBAMA