Born near Knoxville, Tennessee, McMeans first began practicing medicine in the 1840s in Greenville, South Carolina.
In the fall of 1859, McMeans moved to Virginia City, Nevada after the Comstock Lode silver strike.
When the news of the firing on Fort Sumter reached Virginia City in 1861, McMeans announced that he would capture Fort Churchill for the Confederacy, but was quickly disabused of this notion by news of a detachment of Union soldiers heading from Fort Churchill to Virginia City.
After the Civil War, he organized the Democratic Party in Nevada and became its first chairman.
He eventually moved to Reno, where he died at age 70 in 1876.