The Ninth Census of the United States, Volumes 1 and 2
The Census was taken in 1870, and these volumes were published in 1872.
Volume 1 - The Statistics of the Population of the United States Embracing the Tables of Race, Nationality, Sex, Selected Ages, and Occupations.
Volume 2 - The Vital Statistics of the United States Embracing the Tables of Deaths, Births, Sex, and Age as well as statistics on "the blind, the deaf and dumb, the insane, and the idiotic."
These 2 volumes discuss information from the 1870 Census.
A third volume was also printed in 1872 but is not present. (It covered industry and wealth and included tables of weath, taxation, public indebtedness, agriculture, mining, occupations, and more.)
The books were printed by the US Government Printing Office in 1872.
They are illustrated with maps and charts.
They are hardcover with leather spines and corners.
These are large books. Each of the two volumes measures 9-1/4" by 11-3/4" and is more than 1-3/4" thick.
The covers are worn. The leather is cracked, chipped, and in poor condition. It has rubbed areas, and there are rubbed areas on the top and bottom edges of the boards. The spines of both volumes are cracked. There are a few pages with creases and some stains.
Volume 1 has writing inside the front cover. 
Volume 2 has lost approximately half of the leather over the spine. What remains is vertically split. The back cover is present but is separated from the rest of the book. The first page, with no print on it, is also present but loose. The front cover is very loose and being held on by a single old string. It may come completely loose during shipment.
The pages of both volumes have tanned with age.
Please see photos.