By 1860, large-scale plantation agriculture, rare in southern Florida, started to develop in the Tampa Bay area. Cotton plantations and open cattle herding were successful. Census figures from 1860 show the Pinellas peninsula was up to 82 families, with 381 individuals, including 36 Whitehursts and eight McMullens.

The War Between the States

In 1861, the Civil War broke out, changing the future of Clearwater. Florida was actively engaged as part of the Confederacy. Almost every young man in the area responded to the call to arms. McMullen organized a military company called the Home Guards. Men from Clearwater and outlying areas became members, including William Campbell, J.D. Rogers, A.C. Turner and David B. Turner. The Home Guard joined other Florida companies on battlefields to the north.

The Women's Club history of clearwater (1917) described what life in Clearwater was like while the men were away.

"Several gun boats made raids on Clearwater, carrying [away] provisions and supplies of all kinds. Many hardships were endured here. The women and children had, to a great extent, to provide for themselves. It was impossible to buy salt, and the half-grown girls had to procure it by boiling salt water. A large wash pot was taken to the beach and kept full of water, a brush fire built under it, and by night, two or three quarts of gray salt rewarded them for their labors."

Though they toiled alone, the women were not harmed by Union soldiers in this "war of gentlemen."

For a time the post office was closed in Clearwater, opening up again in Bellaire, but later returning to service in Clearwater in 1865.