To understand voting patterns in US presidential elections, it is important to understand the role that slavery played in how various regions of the country vote to this day.

When Abraham Lincoln ascended the presidency on March 4, 1861, the major issues facing the country at the time were the abolition of slavery as an institution in the south; whether any of the new states that were to be admitted into the Union were to be free states or slave-holding states and in fact and whether the Union itself would remain intact, given the vitriol between abolitionists in the north who wanted an end to slavery and southerners who were hell bent on preserving slavery at any cost.

During this period in American history, most members of the newly-formed Republican Party (1854) were northerners who were opposed to slavery, some on moral grounds but some because they did not want to see the south gain more power in Congress by having more states admitted as slave states. Under the previous “Missouri Compromise” of 1820, which had kept the Union from splintering over the always-simmering and divisive issue of slavery even then, it was agreed that slavery would be prohibited in any new state north of the 36th parallel. However the Kansas-Nebraska Act, passed in 1854 with heavy Democratic support, overturned that. Under the Kansas-Nebraska Act, each new state would get to determine whether it wanted to be a free or slave-holding state, by what was called “popular sovereignty”. The threat of a parting of ways between north and south was now imminent. Both southerners and northerners rushed to populate the areas of the interior territories, which were part of the vast Louisiana Purchase made from the French in 1803, in the hope of turning those places either slave or non-slave, as they prepared for statehood and entry into the Unites States.

When Abraham Lincoln, a Republican from Illinois became president in March 1861, there were 34 stars on the American flag, each representing a state. Within weeks of his inauguration, 11 of those states—the slave-holding states of Virginia, North Carolina, South Carolina, Georgia, Florida, Alabama, Tennessee, Mississippi, Louisiana, Texas, and Arkansas— promptly seceded. These 11 southern states became the Confederate States of America and elected Jefferson Davis as their president. For them, the threat of the abolition of slavery (as the Republicans had campaigned for) represented a direct attack on their way of life. In their reading of the Constitution, they collectively believed that the American Constitution guaranteed their right to own private property and slaves were seen not as human beings to be accorded equal rights with the White man, but rather as the private property of whites and subservient to them.

Confederate Vice-President Alexander Stephens, in a famous speech known as the Cornerstone Speech, declared: “Our new government is founded…upon the great truth that the Negro is not equal to the white man; that slavery subordination to the superior race is his natural and normal condition.” White supremacy was now the official doctrine of the Confederacy. On April 12, 1861, Jefferson Davis ordered Confederate troops to attack the Union garrison of Fort Sumter in Charleston, South Carolina. The Civil War had begun.

Over the next four years, the north and south – Union and Confederacy — engaged in a bitter civil war. Over 620,000 men, women and children would be killed, more than the number of Americans killed in all subsequent wars, including World Wars I & II, Vietnam, and Iraq – combined.

On January 1, 1863, Abraham Lincoln issued the Emancipation Proclamation, freeing all slaves in the south and encouraging them to join the Union army and fight their former slave masters. Said Lincoln at the time: “If slavery is not wrong, nothing is wrong. I can not remember when I did not so think and feel.” The south never forgave Republicans. After four years of war, the north, with its bigger population, greater resources and far greater infrastructure, prevailed and the war ended on April 9, 1865.

During this time, Lincoln had gone on to win a second term in November 1864, despite the war’s ebbs and flows. In fact, during the summer of 1864, the war was going so badly for the north, that many northern Democrats had become war-weary and wanted a negotiated peace with the south. Up to August 1864, many, (including Lincoln himself), thought he would lose the election and many urged him to, under the circumstances, postpone the election. Lincoln, a principled man, demurred: “We cannot have free government without elections; and if the rebellion could force us to forego, or postpone a national election, it might fairly claim to have already conquered and ruined us.”

Things changed dramatically for Lincoln, when in September 1864, Union General William Sherman saw victory in the Battle of Atlanta, a southern stronghold. Victory for the north now looked in sight. With three more previously unincorporated states now added to the Union between 1861 and 1864 – Kansas, Nevada and West Virginia, (a breakaway from Confederate Virginia) – Lincoln won the election of 1864 by a landslide, winning 23 of 26 states and became the first two-term president in almost 30 years (the previous eight presidents all lost their re-election bids). However, Lincoln, a canny politician, had ditched his previous Vice-President Hannibal Hamlin and picked Andrew Johnson – a Democrat – as his running mate and both ran under a “National Union Party” ticket. Johnson, whom he had appointed as military governor of Tennessee when Union forces had recaptured parts of that state in 1862 was a “War Democrat,” and a former Tennessee Senator and the only member of Congress from the south, who had not resigned his post when his state seceded. “War Democrats” were those democrats who accepted war with the south to preserve the Union as opposed to “Copperhead” Democrats, who wanted to halt the Civil War and readmit the south without any preconditions, at all costs. Johnson however, was also a slave-owning southern Democrat who sympathised with the slave-holding ways of the south.

Shortly after the Lincoln’s second inauguration on March 4 1865, Lincoln was assassinated (April 15, 1865) in a conspiracy by southern sympathisers to kill Lincoln, Andrew Johnson and William Seward, his secretary of state. Johnson and Seward survived and Johnson was appointed president the same day Lincoln was killed.

With the war now ended, and their president martyred, Republicans in Congress, wanted to impose harsh penalties on the south. With overwhelming majorities in Congress, they passed the 13th Amendment to the Constitution, which banned slavery in the United States. They also required the south to pass the 14th and 15th Amendments to the Constitution, which gave citizenship to blacks and the right to vote, respectively, in order to be readmitted to the Union. Both the south and Johnson (vetoed) refused. Johnson vetoed so many bills proposed by the Republicans – now called Radical Republicans by their detractors – that Johnson was later impeached by them – the first president to suffer that fate – and only survived being removed from office by one vote in the Senate.

Johnson was hated by the Radical Republicans and lost the election of 1868 to Ulysses S Grant, Lincoln’s top general during the Civil War and also a Republican. In the period immediately after the Civil War, known as the Reconstruction era, southern states resisted and stymied Republican efforts in granting equal rights to blacks.

Despite southern opposition, however, blacks enjoyed a brief period of success following the war. During the early years of Reconstruction, and especially during the presidency of Ulysses Grant, blacks and Republicans in the south (the latter derisively referred to as “Carpetbaggers” and the white southern Democrats who worked with them as “Scallywags”), southern blacks enjoyed new-found voting rights and many gained economic power and were elected to Congress and State Legislatures in the south.

It was during the 12-year Reconstruction era that predominantly black universities like Howard University in Washington DC and Moorehouse College in Atlanta (later attended by Dr Martin Luther King) came into being. And the south never forgave the Republicans.

The Reconstruction era also saw the birth of the Ku Klux Klan, which was formed by former Confederate officers in Georgia and Tennessee to further their “lost cause” and to restore the south to its antebellum “glory days.” They elected as their leader former Confederate General Nathan Bedford Forrest who had massacred thousands of Black Union troops even after they had surrendered during the Battle of Fort Pillow in Tennessee during the war. They gave him the title: “Grand Wizard of the Ku Klux Klan” similar to the moniker he went by during the war: “Wizard of the saddle.”

The Ku Klux Klan launched a reign of terror throughout the south with many of its membership being secret: polite citizens by day and terrorists under white suits and hood, intimidating and killing thousands of blacks and white sympathisers by night. The north had won the war, but the Klan was helping the south to win the peace, by chasing Republicans back north and rolling back short-lived gains by blacks. Having succeeded, southern Democrats then enacted “Jim Crow” and anti-miscegenation laws state by state, all across the south; denying blacks the right to vote, own land, attend white schools or marry whites. The south became the stronghold of southern Democrats for the next century. And black progress in the south came to a screeching halt.

It took 100 years for the next major shift in the southern political landscape to come about. After waves of demonstrations across the south, by blacks and liberal whites, led by The Reverend Martin Luther King, for equal rights in the 1950s and 60s, (to fierce oposition and violence from southern politicians), African-Americans were finally given equality under the law and voting rights, with the passage of The Civil Rights Act of 1964 and The Voting Rights Act of 1965 respectively. Both of these Acts were signed into law by Lyndon Johnson (another Johnson from the south who had succeeded another assassinated and beloved northern president – John F Kennedy).

Unlike Andrew Johnson, however, Lyndon Johnson, although a southern Democrat from Texas, and a product of southern segregationists, was not shackled by his Texas upbringing. He understood the twin evils of racism and segregation and thought that such policies had to be overturned. With the signing into law of both bills by “one of their own”, the south now never forgave the Democrats. A sudden wave of defection from the Democratic Party to the Republican Party, all across the south, again took place. The Ssuth now became a sea of Republican red.

With the exception of Virginia, the northern-most “southern” state, almost all of the southern states and many of the newly incorporated states formed from the inland territories, that were later admitted as states: Utah, Nebraska, Wyoming, Idaho; almost always vote as a block for Republican presidential candidates (because of their shared history – many of the people who rushed to these new territories did so to make them slave-holding states and/or did not want to welcome former black slaves to these areas).

So the next time you look at an electoral map of America in any presidential election year, expect to see Republican red all throughout the south and in the central part of the country, and Democratic blue in the north and the non-slave holding states of California and Oregon, out west.

The legacy of slavery and voting patterns in the US are as strong a force today, as it was 160 years ago, during the age of Lincoln. The difference: the roles are now reversed. Republican ideals of civil rights for blacks, welcoming of foreigners and outward-looking internationalism, as examples of policy positions, have now become Democratic ideals, while erstwhile southern Democratic nativism, embrace of white nationalism and go-it-alone isolationism, are now the policy position of a certain wing of the Republican Party (personified by Donald Trump) in the 21st century.

Barrington Greene is a Jamaican writer