Blount, 60, was sentenced Thursday in Greenville by U.S. District Judge W. Allen Pepper Jr.
In April 2010, a jury found the former businessman guilty of running down Esther Hagemann in April 2009 as she rode south through Chickasaw County to visit friends in Jackson.
He was convicted of negligent manslaughter while under the influence of morphine.
Blount was due for sentencing later in 2010 but ran away from house arrest while free on bond. U.S. marshals found him six months later in Louisiana and returned him to Oxford, where he's been held ever since.
Pepper also sentenced Blount to five years of supervised release once he leaves prison.
He faced up to 33 years in prison and a $500,000 fine.
The U.S. Bureau of Prisons will determine where Blount serves his term. He remained in federal custody after his sentencing.
The case was investigated by the National Park Service, which polices the Natchez Trace, and was prosecuted by Assistant U.S. Attorney Robert Mims.