
History is full of union and division. Whether people joined together or not This Week in History, we’ll look at four events where people either split apart or came together despite the divisions that separated them. Let’s dive in!
On Oct. 18, 1469, 552 years ago, Ferdinand of Aragon married Isabella of Castille, uniting all of Spain and beginning the Spanish Golden Age.
When the Roman Empire fell in the 5th century A.D., western Europe lay in a chaotic mess of various kingdoms constantly at war with one another. The 15th century, almost 1000 years later, saw the unification of such kingdoms into the modern nation-states we know today. Spain was the first to do so, beginning with the royal wedding of the millenium.
Ferdinand was the heir to the throne of Aragon (eastern Spain and home of modern-day Barcelona) while Isabella was the sister of Henry (Enrique in Spanish), the King of Castille (central Spain and home of Madrid). Henry was not exactly a popular leader, bearing the nickname, “The Impotent,” by his people. Ferdinand and Isabella seized the Castillian throne from Henry, and the duo ruled over the newly-formed Spanish nation.
Known as the “Catholic Monarchs,” Ferdinand and Isabella were fiercely loyal to the Roman Catholic Church and vowed to “cleanse” Spain of its heretics. The couple launched a military campaign, the “Reconquista,” to conquer the remaining independent Spanish territories and expel the Moors (North African Muslims) out of Granada and ultimately out of Europe. Remaining Spanish Jews and Muslims were forced to covert to Christianity, or leave Spain and never return.

Ferdinand and Isabella’s reign marked the beginning of the “Age of Exploration” with the sponsorship of Columbus’s fateful voyage across the Atlantic. Flying under the Spanish flag, several “conquistadors” claimed land in North, Central and South America in the name of Ferdinand, Isabella and their heirs. While such colonies brought Spain tremendous wealth and power, it also brought about the mass destruction of the Indigenous civilizations already established in the “New World.”
Also on Oct. 18, in 1767, 254 years ago, the Mason-Dixon Line officially divided the “North” and “South” of what would become the U.S.
This line began when two families hired Charles Mason and Jeremiah Dixon to clearly define the boundaries of their adjacent properties. It eventually divided the two warring cultures of the U.S., erupting into the bloodiest conflict of U.S. history. As English colonists began settling the East Coast of what would become the U.S., wealthy English families requested land from the English king to establish their own colonies in the New World.
The Penn and Calvert families did exactly that to establish religious havens for their people in North America. The Penns were Quakers and established Pennslyvania, while the Calverts were Catholic and established Maryland. Neither group was accepted by the Church of England, therefore they both sought greener pastures in North America.
The border between Pennsylvania and Maryland would come to prominence over the next 100 years as the line between North and South, Democratic and Republican states and slave states and free states. Slaves like Harriet Tubman would escape the South by crossing the border into Pennslyvania.

Interestingly enough, while Maryland was a slave-holding state that considered itself “Southern,” the Mason-Dixon Line was not the boundary between the North and South during the Civil War. Instead, the Potomac River, the border between Maryland and Virginia, divided the two factions because Washington, D.C. lay between them. President Lincoln allowed Maryland to continue owning slaves in order to protect the U.S. capitol from being surrounded by the Confederacy.
Again on Oct. 18, this time in 1898, 123 years ago, Puerto Rico became a part of the U.S. at the close of the Spanish-American War.
When the average American thinks of the many wars the U.S. fought in, the Spanish-American War rarely comes to mind. Like many nations of the late 19th century, however, the U..S sought to become an imperial power, with territorial claims around the world like those of Western European nations. Over the course of a few months, the U.S. wrestled with the crumbling Spanish Empire and took control over Puerto Rico, Guam and the Philippines.
The U.S. government would try to “Americanize” the island by granting American citizenship to Puerto Ricans in 1917, even making efforts to enforce English as the official language. Puerto Rico, however, was able to uphold its cultural traditions over the next century and even draft its own constitution in 1952.
The question of Puerto Rican statehood has loomed throughout the entirety of its history as a U.S. territory. In 2020, a majority of Puerto Ricans voted in favor of statehood in an island-wide referendum, however, it would require congressional action to move forward.

On Oct. 18, 1961, 60 years ago, the American musical film, “West Side Story,” was released in movie theaters nationwide.
Based off of the Broadway musical of the same name which took its inspiration from Shakespeare’s “Romeo and Juliet,” “West Side Story” is arguably the greatest movie musical of Old Hollywood. Set in the tenements of the mid-century Manhattan, the film chronicles the tragic story of star-crossed lovers, Tony and Maria, who fall for each other despite the ethnic divides of their rivaling gangs.
“West Side Story” was the darling of the 1962 award season, winning 10 out of the 11 Academy Awards it was nominated for, including Best Picture and Best Supporting Actress for Rita Moreno, the first Latinx actress to win an Oscar.
The film has been criticized in recent years for its lack of Latinx actors in Latinx roles. The 2021 Steven Spielberg remake, set to release in December, promises to feature a diverse cast with Moreno in a featured role.