Like any poem or piece of literature, it is the reader’s interpretation. But here is the gist. This poem is a bit tricky because it seems to be lamenting the life of rustic prairie of the past and the foreboding industrialization of the future. But, there are verbal cues that let you know that this poem is actually about nostalgia for the past and hope for the future.
The flower-fed buffaloes of the spring
In the days of long ago,
Ranged where the locomotives sing
And the prairie flowers lie low: (1-4)
The first two lines use the past tense and they are nostalgic. The buffaloes used to roam here. The next two lines are present tense. The locomotives “sing.” They don’t roar or crunch. Using “sing” might be sarcastic but I don’t think that’s the case here. It seems like “sing” is used to mark the presence of the locomotive as useful or pleasant. And although the buffalo may be gone, the prairie flowers are still here. This fact will be important later in the poem.
In the next four lines, the wheels spin by in “the spring that’s still sweet.” Things have changed but the prairie is still sweet.
The next two lines repeat the nostalgic lament.
But the flower-fed buffaloes of the spring
Left us long ago, (9-10)
The word choices in the next line can be interpreted in one of two ways. If the buffalo “gore” and “bellow” no more, this could mean that their absence is an unfortunate but necessary part of the evolution of history. Also, and this interpretation is more accepted, since the buffalo are gone, they are no longer being slaughtered. They are better off now. Native Americans may have played a major role in killing them off, but westward expansion would have pushed the buffalo and the Native Americans out anyway.
This brings us to the final two lines.
With the Blackfeet lying low,
With the Pawnee lying low. (12-13)
There are no more buffalo to kill. But these last two lines echo the sentiment about the prairie flowers. The buffalo may be gone but the flowers, Blackfeet and Pawnee are still there. So, there are still traces of the past despite the onward marching of the locomotive of the future. This poem looks back fondly and looks forward hopefully . You may even interpret the semblance between the flowers and the Blackfeet and Pawnee as a plea to keep what remains of the prairie’s past. Linsay was relatively liberal for his time, so I would wager to say that he was commenting on the dwindling Native American population.