"The sky is the limit" (1909)

[Laurence Horn]

At 7:14 PM -0500 1/25/04, Bapopik at AOL.COM wrote:
>    I saw the movie SEABISCUIT (2003) on the flight home.  There were several
>anachronisms.  "Tex-Mex" appears on a background billboard at Tijuana in the
>early 1930s.  Also, "Hope and Crosby" is mentioned in the 1930s, before their
>first road picture together (ROAD TO SINGAPORE, 1940).  I sent that one to
>www.moviemistakes.com.
>    One character uses the word "shit" frequently in the 1930s.

How can we tell that one is an anachronism?