During the 40 years of the pioneer era, the original settlers cleared 104,000 acres of farmland, built churches with a seating capacity of 15,100. the settlers also, constructed 4 merchant mills, a cotton factory, 8 saw mills, 14 grist mills and 6 distilleries. The County Seat of McDonough was prospering as one of the leading commercial centers in Upper Georgia and then a new factor appeared on the scene. The Monroe Railroad and the Georgia Railroad brought much prosperity to the Henry County. The old Indian Trail based roads where replaced and towns along the railroads boomed. Merchants and lawyers deserted McDonough for the new boomtowns.

During the periods of 1860's and 1870'5 the county faced two decades of tumult, upheaval, disruption and destruction. The Yankees invaded the towns and blame the settlers for prolonging the War. The Yankees vandalized and burned churches, schools, and homes. With the War Between the States over two extraordinarily profound changes occurred in Henry County: First, the sad and peculiar institution of human slavery ended; Second, the people of Henry County, Black and White, found themselves in a state of near total poverty and destitution. With the war over and the men home the population resumed to its natural increase. Settler’s concentrated on tenant farming and share-cropping during the reconstruction period.

For a 40 year period from 1880 to 1920 Henry County acquired much wealth from its Cotton Kingdom. The construction of the Georgia Midland and Gulf Railroad in 1886 brought McDonough back to life. Attorneys and newspapers moved their offices from Hampton back to McDonough. Increased cotton production and higher cotton prices led to an unprecedented prosperity. Cotton acreage in Henry County reached its historic peak in 1919 with a total acreage of 66,238 acres. The progress and prosperity of Henry County did not last long when the cotton boll weevil brought the cotton crop to a total loss in 1920.

“The Boll Weevil Depression" lasted from 1920 to 1940. The population of Henry County topped out at over 20,000 in 1920 and by 1940 had declined by 25% to about 15,000. Most of the banks closed, thousands lost their homes, farms and businesses because they couldn't pay their creditors. For two decades everything in Henry County was in decline. Many present day residents recall this period with stories of getting by, of cars on blocks in the barn because they couldn't afford a gallon of gas and of general hard times. The economy of Henry County did not turn up again until World War II. The biggest trend, which developed during this period, was living in the country and working in Atlanta.

During the first part of this era Henry County was still very rural and relatively isolated from Atlanta. This was to be changed forever by the construction of l-75 through the heart of Henry County. Work began on the Interstate in 1966 and the Interstate was open to traffic all the way through the County in the fall of 1969. This brings us to our sixth and present era, "1-75 and Beyond".

During the twenty year period from 1970 to 1990 the population of Henry County exploded. In 1970 thepopulation finally regained its 1920 level of 20,000; up from the 1940 low of 15,000. It took 50 years for the population to recover from the Boll Weevil Depression. Between 1970 and 1990 the population almost tripled. Henry Cunty population has almost doubled again since 1990. Projections for the Henry County population will top 200,000 by 2010.