The Twentieth Maine A painting depicts Union Army Col. Joshua L. Chamberlain ordering the men of the 20th Maine Infantry to run down Little Round Top and push back the Confederate soldiers during the Battle of Gettysburg, July 2, 1863. SHARE: Download: Full Size (0.36 MB) Credit: National Guard Bureau/H. Charles McBarron VIRIN: 180320-Z-KE703-1005C.JPG Photo Gallery