The layout of the stars was officially standardized in 1912, while the colors were standardized in 1934. Starting in 1818, the new flags were introduced on July 4th of the year listed.

In 1942, the Federal Flag Code was passed to provide uniform guidelines for the display of flags.

In the infographic below, the most typical flag of the period is listed first, with alternate patterns and special flags listed after.

One frequent complaint from flagophiles about many movies is the incorrect positioning of a flag in the vertical position.

According to the code, the blue part should be on the left.

Flag trivia: there is only place where an official flag is never brought to half-mast during a period of mourning. That place? The Moon.

H/T Eric-hart