The Union assault on Petersburg, Virginia, began on this day. The 4th Wisconsin Light Artillery and 5th, 6th, 7th, 19th, 36th, 37th and 38th Wisconsin Infantry regiments took part in this four-day battle. Union troops repeatedly attacked smaller Confederate forces without being able to take the city. On June 15, Union forces failed to take advantage of their unexpected arrival and delayed their initial attack. This gave Confederate troops time to reinforce their positions.