Because I could not stop for Death — Washington Monument

"Because I could not stop for death (firmly) the carriage, he kindly stopped it for me."-an alternative reading of the first two lines.

Dickinson seldom travelled, but she did visit Washington once. This poem is about her romantic ride with a gentleman to Washington Monument. The key is to find out the place she described in line 17 to 20, a very high building.

Because I could not stop for Death1
He kindly stopped for me-
The Carriage held but just Ourselves-
And Immortality.

We slowly drove-He knew no haste 5
And I had put away
My labor and my leisure too,
For His Civility-

We passed the School, where Children strove 9
At Recess-in the Ring-
We passed the Fields of Gazing Grain-
We passed the Setting Sun-

Or rather-He passed Us-13
The Dews drew quivering and chill-
For only Gossamer, my Gown-
My Tippet-only Tulle-

We paused before a House that seemed 17
A Swelling of the Ground-
The Roof was scarcely visible
The Cornice-in the Ground-

Since then-'tis Centuries-and yet 21
Feels shorter than the Day
I first surmised the Horses' Heads
Were toward Eternity-
(F.479/J.712)
[1] stop for Death:: to stop firmly the carriage (in line three).
[2] He:: a gentleman who helped Dickinson to stop the carriage.
[3] just Ourselves:: the two were undisturbed.
[4] immortality:: she wished the ride would last forever.
[5-8] We slowly drove, His Civility:: they had a casual ride.
[9-12] School, Fields:: they passed a school and some fields unidentified.
[13] He passes Us:: she felt the world was not moving.
[17-20] House, Swelling, Roof, Cornice:: a description of Washington Monument; its cornerstone was laid on July 4, 1848 and the monument officially opened in 1888. This poem was written around 1862.
[19] Roof was scarcely visible:: a very high building.
[20] Cornice in the Ground:: a low cornice.
[21, 22] Centuries, Day:: she missed the ride greatly.
[23] Horses' Heads:: the original design of the monument had horses, omitted due to lack of funding. The drawing with horses was printed in the tourist guide of Washington by Morrison (1852), a book in the Dickinson's family library.
[24] Eternity:: a hint on the answer, a monument for eternal fame.
[23-24] surmised, Eternity:: she realized that such good time would never come again, though she hoped.

WASHINGTON MONUMENT. . . . to erect at the seat of government to the memory of Washington, from voluntary contributions. . . . 50 feet square at the base, and 500 feet high, . . . This great work is rapidly rising, and has already been carried up nearly one hundred feet. ─ Morrison's Stranger's Guide to the City of Washington and its Vicinity (1852).
The original design has four horses.