a river which Byron, Wordsworth, and Longfellow all highly praised?

Answer 1

I would guess the Thames

z

Answer 2

the river Rhine

"The castled crag of Drachenfels, Frowns o'er the wide and winding Rhine, Whose breast of waters broadly swells Between the banks which bear the vine, And hills all rich with blossom'd trees, And fields which promise corn and wine, And scatter'd cities crowning these, Whose far white walls along them shine. "
Author: Lord Byron (George Gordon Noel Byron)
Source: Childe Harold (canto III, st. 55)


The Rhine! the Rhine! a blessing on the Rhine!
Author: Henry Wadsworth Longfellow
Source: Hyperion (bk. I, ch. II)
Beneath me flows the Rhine, and, like the stream of Time, it flows amid the ruins of the Past.
Author: Henry Wadsworth Longfellow
Source: Hyperion (bk. I, ch. III)


Wordsworth:
"-born forward by the Rhine,
The living landscapes greet him, and depart;
Sees spires fast sinking -- up again to start!
And strives the towers to number, that recline
O'er the dark steeps, or on the horizon line
Striding with shattered crests his eye athwar"