The answer is a Clydesdale horse.
Here's why:
* Big milky-white horse: Clydesdales are known for their large size and often have a white coat with black points (legs, mane, and tail).
* Risen to the top in America: Clydesdales are famous for their association with the Budweiser brewery, which uses them in their marketing campaigns and parades.
* Can truly say of crop: This relates to the phrase "cream of the crop," which means the best of the best. Clydesdales are considered a prestigious breed in America, so they could be considered the "cream of the crop" of horses.
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