Conversation so far:
what did the union flag look like in the civil war
The union red, white and blue standard remained mostly unchanged during the war other than to add a star when the 34th state, Kansas, was admitted to the Union
how were the stars arranged in the union flag during the civil war
There were a number of different star patterns on the Civil War Union flags. Since there was no official star pattern, people designed their flags as they saw fit.

Question: when was a pattern introduced
Self-contained rewrite: when was an official star pattern introduced for the american flag