On April 23, 1755, George Washington met with General Edward Braddock, and possibly with Benjamin Franklin, at a West All Saints Street tavern in Frederick to plan the British attack on Fort Duquesne. The building was demolished in 1913 to make way for a milk plant.
On April 23, 1819, Alexander Contee Hanson, Jr., son of former Maryland chancellor Alexander Contee Hanson and grandson of John Hanson, and a former member of both houses of the U.S. Congress, died at “Belmont,” Frederick County.
On April 23, 1832, the Baltimore & Ohio Railroad tracks to Point of Rocks were completed.
On April 23, 1875, Josiah Pennsyl, who entered the Union Army in Frederick and a sergeant with Company G, 8th U. S. Calvary, received a Congressional Medal of Honor for his "gallantry in action" at Upper Washita, Texas, on September 11, 1874. This engagement is known as The Battle of Lymans' Wagon Train.
On April 23, 1893, the “Frederick and Middletown Valley Passenger Railroad Company” was incorporated.
On April 23, 1948, the Frederick Chamber of Commerce and The Historical Society of Frederick County became owners of the estate of George Alfred 'Gath' Townsend west of Burkittsville. The purchase price was $3,500 for the 105-acre property.