You know the story of the Imagist movement: Ezra Pound, on a whim, when sitting in the Tea Room of the British Museum with his ex-girlfriend Hilda from Pennsylvania and her new attachment Richard Aldgington, came up with the term, and later they wrote a manifesto about it, since such things were being done at the time. Then Amy Lowell, a rich New Yorker, took over the idea and formed her own group which excluded Pound, using Imagism as her calling card: Pound called the new(ish) brand of thing they were writing 'Amygism' and started playing around with Wyndham Lewis and what he called the Twentieth Century Vortex.
What you perhaps did not know is that Lowell printed, for three years, a yearly anthology of these later Imagists, and that you can find and read these anthologies. And if you only know the above part of the story, you may not know the following:
-DH Lawrence was a member and did some good work in the volumes (no turtle poems though)
-Aldington himself is a weak-kneed version of HD's stuff
-HD is a rock star: read in a group like this she's pretty clearly the single best thing they have going, and her single poem "Eurydice" stands clear of all challengers as the most clear and intense poem in a group who pride themselves on clarity and intensity
-Lowell herself is not a contemptible poet! Because the rest of the twentieth century hinges more or less around Pound, I had always thought she must be a joke of a byproduct. She's quite good in various formats, including the 'prose poem' that very few people can make anything of.
If nothing else, this is a good historical piece to get hold of.