As Jen explained, the reason behind the divergence in verb tense is the difference in dialect (typically) between American and English usage of collective nouns.
For more background on the 'why' in American usage, with "Corporation" as the example:
An artificial being created by law and composed of individuals who subsist as a body politic under a special denomination with the capacity of perpetual succession and of acting within the scope of its charter as a natural person. (Bouvier's Law Dictionary)
The words person ... include(s) corporations, companies, associations, firms, partnerships, societies, and joint stock companies, as well as individuals (US Code: Title 1, Chapter 1, ¶1)
A hallmark example of a collective group being considered as an individual person comes in the form fo the East India Tea Company. This company rose to such famed status and influence, yet, for the record could only ever be considered "a fictional person, a legal person, or a moral person (as opposed to a natural person)."
Moreover, in the U.S. (as in most other countries, U.K. included), "[a] corporation is legally a citizen of the state (or other jurisdiction) in which it is incorporated (except when circumstances direct the corporation be classified as a citizen of the state in which it has its head office, or the state in which it does the majority of its business)."
Note though, at all times the concept, almost half a millenia old, that collective groups are persons, not peoples.