I found a fun review of the Blu-ray re-release of the film in 2015.
Although the film’s portrayed politics may echo events and debates that have occurred in the succeeding 239 years, 1776 is far more than political drama. The musical humanizes historic figures through romantic interludes and sometimes bawdy language, which has been returned from the stage version to the new director’s cut. Hunt comments that the humor “still works… Every joke landed. Nothing seems dated at all.”
Go read the whole thing.