I counted the pages devoted to 19th century poets in eight anthologies of American poetry. With one exception, the books all try to cover all of American poetry, from the Anne Bradstreet or what have you to their own day. The Library of America anthology is in two volumes, and covers the 19th century only. Robert Frost is included as a reference point. Clicking should enlarge the table:
I find this all a little too interesting. Look at that stuffy 1912 Yale Book of American Verse - no Dickinson, no Melville, almost no Whitman. Just Fireside Poets as far as the eye can see. The 1900 E. C. Stedman anthology is much more daring.
Note how David Lehman's 2006 New Oxford anthology, compared to Richard Ellman's 1976 version, decimates the 19th century poets. He puts everything before the 20th century in a vise, and freezes the pre-World War II poets, in order find room for more recent poets. Look what he does to poor John Greenleaf Whittier - 39 pages in 1976, 6 in 2006.
Another way to see this is to look at the rankings. I report the top 6 or 7:
Note the rise of Walt Whitman from obscurity to crushing eminence. Dickinson, and to a lesser degree Melville, also show nice, steady increases in ranking. The Fireside Poets do terribly. Holmes and Lowell completely shrivel, Bryant fades with dignity, Whittier hangs on with the long "Snow-Bound" (typically half of his pages). Only Longfellow maintains any sort of parity.
This is one way that canon formation works. Editors have limited space in their anthologies. If they want to add anything, they have to cut something else. A publisher can add pages - see the "Total Pages" row - but there are physical limits.
Whitman was clearly underrated. Dickinson and Melville, too. Or maybe now we greatly overrate them. Based on my own reading, this progression has been exactly right. But I live now, so of course my tastes, prejudices, and judgments are not those of a reader of 1900. I guess I could be a cranky contrarian. That's fun. Actually, I would say that Longfellow is now a bit underrated, and would also note that Poe is probably not served well by this page-counting measure, since he did not write much verse, although he seems to do all right in the rankings.
This is all motivated by my reading of a collection of John Greenleaf Whittier poems, the oddly labeled John Greenleaf Whittier's Poetry "by" Robert Penn Warren. Not sure about that "by" - Warren includes a long essay on Whittier, but I'm pretty sure the 150 pages of poems are by Whittier. The selection (and length) is similar to the Brenda Wineapple Library of America volume. The heart of the problem is that despite the seven thick volumes of John Greenleaf Whittier poems, there are nowhere close to 150 pages of good poems. Maybe forty. The great puzzle to Warren is not how a great poet wrote so much junk, but how a bad poet occasionally wrote a masterpiece.
David Lehman is too hard on Whittier, but to anyone who classifies him as the third or fourth or fifth best 19th century poet, I say: overrated!
All errors my own (and likely), data available by request, etc. Bibliography, in chronological order:
An American Anthology: 1787-1900 (1900), ed. Edmund Clarence Stedman, Greenwood Press reprint, available as a Google Books PDF.
Yale Book of American Verse (1912), ed. Thomas R. Lounsbury, Yale University Press.
The Oxford Book of American Verse (1927), ed. Bliss Carman, Oxford University Press.
The Oxford Book of American Verse (1950), ed. F. O. Matthiessen, Oxford University Press.
American Poetry (1965), eds. Gay Wilson Allen, Walter B. Rideout, and James K. Robinson, Harper & Row.
The New Oxford Book of American Verse (1976), ed. Richard Ellman, Oxford University Press.
American Poetry: The Nineteenth Century, Vols. 1 and 2 (1993), ed. John Hollander, Library of America.
The New Oxford Book of American Verse (2006), ed. David Lehman, Oxford University Press.