The most famous poem of William Ross Wallace

It's "The Hand that rocks the Cradle Is The Hand That Rules The World" from 1865.

Blessings on the hand of women!

Angels guard its strength and grace,

In the palace, cottage, hovel,

Oh, no matter where the place;

Would that never storms assailed it,

Rainbows ever gently curled;

For the hand that rocks the cradle

Is the hand that rules the world.

Infancy's the tender fountain,

Power may with beauty flow,

Mother's first to guide the streamlets,

From them souls unresting grow—

Grow on for the good or evil,

Sunshine streamed or evil hurled;

For the hand that rocks the cradle

Is the hand that rules the world.

Woman, how divine your mission

Here upon our natal sod!

Keep, oh, keep the young heart open

Always to the breath of God!

All true trophies of the ages

Are from mother-love impearled;

For the hand that rocks the cradle

Is the hand that rules the world.

Blessings on the hand of women!

Fathers, sons, and daughters cry,

And the sacred song is mingled

With the worship in the sky—

Mingles where no tempest darkens,

Rainbows evermore are hurled;

For the hand that rocks the cradle

Is the hand that rules the world. 

Edgar Allan Poe wrote about William Ross Wallace in Marginalia:

He, now and then, permits enthusiasm to hurry him into bombast; but at this point he is rapidly improving; and, if not disheartened by the cowardly neglect of those who dare not praise a poetical aspirant with genius and without influence, will soon rank as one of the very noblest of American poets. In fact, he is so now.

Popular in his time, largely forgotten today.