What great births you have witnessed! The steam press,
the steamship, the steel ship, the railroad,
the perfected cotton-gin, the telegraph,
the phonograph, the photograph, photo-gravure,
the electrotype, the gaslight, the electric light,
the sewing machine, and the amazing,
infinitely varied and innumerable
products of coal tar, those latest and strangest
marvels of a marvelous age.
And you
have seen even greater births than these;
for you have seen the application
of anesthesia to surgery-practice,
whereby the ancient dominion of pain,
which began with the first created life,
came to an end in this earth forever;
you have seen the slave set free, you have seen
the monarchy banished from France, and reduced
in England to a machine.
Yes, you have seen much —
but tarry yet a while, for the greatest
is yet to come. Wait thirty years, and then
look out over the earth! You shall see
marvels upon marvels added to these
whose nativity you have witnessed;
and conspicuous above them you shall see
their formidable Result — Man at almost
his full stature at last! — and still growing,
visibly growing while you look. In that day,
who that hath a throne, or a gilded privilege
not attainable by his neighbor, let him
procure his slippers and get ready to dance,
for there is going to be music.
Abide,
and see these things! Thirty of us who honor
and love you, offer the opportunity.
We have among us six hundred years,
good and sound, left in the bank of life. Take
thirty of them — the richest birth-day gift
ever offered to poet in this world —
and sit down and wait. Wait till you see that
great figure appear, and catch the far glint
of the sun upon his banner; then you
may depart satisfied, as knowing you
have seen him for whom the earth was made,
and that he will proclaim that human wheat
is worth more than human tares, and proceed
to organize human values on that basis.

From Mark Twain’s letter to Walt Whitman for his 70th birthday, written May 1889.