The rectangular battle flag of the Army of Tennessee, Confederate States of America.<br>
Note: The most usual form of the historical Confederate battle flag on land was either square or slightly rectangular (close to square), as in the final Confederate national flag...
<a href="https://en.wikipedia.org/wiki/William_Porcher_Miles" class="extiw" title="w:William Porcher Miles">William Porcher Miles (1822-1899)</a> <br> (Vector graphics image by <a href="//commons.wikimedia.org/wiki/User:Crotalus_horridus" title="User:Crotalus horridus">Crotalus horridus</a>)
1863
SVG adapted from <a rel="nofollow" class="external text" href="http://americanfootsteps.wordpress.com/journal/">this image</a>