I found a reference about Meucci on an Italian-American website. If true, he would indeed be the first inventor of the telephone. It was in 1849, in Cuba; since Meucci was born in Italy and only immigrated to the US in 1850, then the telephone could not be considered an American invention.
If this is true, Congress would not be "rewriting history" but correcting the accounts of history, since history is what it is. Also, it cannot be said that Congress is doing this to "Americanize" the invention of the telephone, since Meucci had even less ties to the US (at the time of the invention) than did Bell. However, it's difficult to determine the truth of this account, since there is probably a scarcity of documentation, and the web site I found does not provide any other references.
In any event, it seems that Bell invented the telephone independently, and was certainly instrumental in commercializing it, while Meucci did virtually nothing with it. (analogous to the Wright Bros. vs. Pearse on powered flight)
Anyway, here's the link, draw your own conclusions.....