What was the future of America, according to Senator Beveridge? How did he want Americans to protect this future?

A commercial empire throughout the world - - which Americans should guard with military might as needed.

Senator Albert Beveridge, elected to the Senate in 1899, was all about projecting American power and commercial interests in unabashed imperialism. You can find a powerful speech of his on that subject from 1898, entitled, "March of the Flag."