Following the battle of Stones River Hazen's men, along with the rest of the Army of the Cumberland, stayed in the Murfreesboro area. Hazen's men wanted to commemorate their part of the battle so in the early part of 1863 they built this monument. This marks it as one of the earliest monuments at a Civil War battlefield, and I'm nearly 100% sure that it is the earliest monument in the Western theater. Inside a stone wall they buried their comrades, and inscribed their names on the monument. Time has made the inscriptions hard to read but the park service has placed tablets around the monument so you know what each side has inscribed on it.