The Mother's Day holiday was originally started as a feminist movement to urge all mothers of sons fighting in combat to speak out against war. Its origins date back to England as what it used to be known as "Mothering Sunday," which came from a 16th century Christian practice that enslaved women who would be allowed to visit their children during the weekend (on Sunday, specifically) on an annual basis.
Later, an American feminist named Julia Ward Howe, who penned the Battle Hymn of the Republic (a notorious hymn to Mars), was inspired by the British holiday after becoming repulsed by Lincoln's War Between the States. She planted the seeds of the American version of the day, thus authoring her infamous 1870 poem "Mother's Day Proclamation."
Unfortunately and eventually, the holiday lost its meaning and has since then come to mean honoring your maternal parent (your mother, that is) by taking her out to dinner and/or giving her a personalized "Mother's Day" Hallmark card.
Here's the original poem to commemorate the original holiday (not the silly holiday we have today):
Arise then...women of this day!
Arise, all women who have hearts!
Whether your baptism be of water or of tears!
"We will not have questions answered by irrelevant agencies,
Our husbands will not come to us, reeking with carnage,
For caresses and applause.
Our sons shall not be taken from us to unlearn
All that we have been able to teach them of charity, mercy and patience.
We, the women of one country,
Will be too tender of those of another country
To allow our sons to be trained to injure theirs."
From the voice of a devastated Earth a voice goes up with
Our own. It says: "Disarm! Disarm!
The sword of murder is not the balance of justice."
Blood does not wipe our dishonor,
Nor violence indicate possession.
As men have often forsaken the plough and the anvil
At the summons of war,
Let women now leave all that may be left of home
For a great and earnest day of counsel.
Let them meet first, as women, to bewail and commemorate the dead.
Let them solemnly take counsel with each other as to the means
Whereby the great human family can live in peace...
Each bearing after his own time the sacred impress, not of Caesar,
But of God -
In the name of womanhood and humanity, I earnestly ask
That a general congress of women without limit of nationality,
May be appointed and held at someplace deemed most convenient
And the earliest period consistent with its objects,
To promote the alliance of the different nationalities,
The amicable settlement of international questions,
The great and general interests of peace.