1824

Unity Post Office opens, William Price postmaster

1825

Post office established at Mechanicsville (Olney), Amos Farquhar postmaster

1828

Philip Thomas becomes founding president of the B&O Railroad, the nation's first

1830

Edward Stabler becomes postmaster at Sandy Spring, with post office in his home, Harewood: serves for 53 years

1833

Dazzling meteor shower awes neighborhood

1834

Salem United Methodist Church established at Brookeville

1842

Subscription library formed at Sandy Spring

1844

Sandy Spring Farmers Club (Senior) established; Peruvian guano (bird droppings) introduced to restore fertility of soil exhausted by tobacco cultivation; St. John's Church (Episcopal) established in Olney; Mrs. Porter's Cottage School for the Education of Young Ladies established at Brookeville; runs for 20 years

1845

Elizabeth Ellicott Lea publishes her celebrated cook book