By order of General Grant all the artillery opened upon Vicksburg this morning, and the bombardment continued throughout the day. It is reported that the rebels have lost six hundred, killed and wounded, many of these being killed during the first two hours of the firing. Our left is holding quite tight. The sky was hazy today and the heat at times was very oppressive.
Source: Alexander G. Downing, Edited by Olynthus B., Clark, Downing’s Civil War Diary, p. 123