(WHTM) — The Civil War was supposed to be over in ninety days.

People on both the Union and Confederate sides thought that the war would be decided in just a single battle. In fact, many troop enlistments were for just ninety days.

Then on July 21, 1861, green, undertrained, inexperienced Union troops marched out from Washington D.C. (just before the 90-day enlistments ran out), clashed with green, undertrained, inexperienced Confederates troops near Manassas, Virginia, and got trounced.

The Battle of Bull Run (if you’re Union) or Manasses (if you’re Confederate) ended with a disorganized, messy, panic-stricken Union retreat, which got even messier and more panicky when civilians, who came out from Washington with picnic lunches to watch their boys in blue smash the rebels, added to the chaos of what Confederates called “The Great Skedaddle.”

The very next day President Lincoln signed a bill calling for the enlistment of another 500,000 men for up to three years of service. The notion of the ninety-day war died at Bull Run; people now realized the war was going to be long, brutal-and expensive.

Troops would have to be paid, fed, clothed, and equipped. Horses and railroads were needed to move men and material from here to there. Cannons would have to be forged, the Navy had to be expanded to blockade the South, and how was the Union going to raise the billions-yes, billions, of dollars needed to pay for all of it?

Before the war, the United States raised most of its money with tariffs and customs duties. The Federal government was leery of issuing bonds back then, usually only resorting to them in times of war. When the Southern states began leaving the Union, Congress passed bills in February and March of 1861 to issue $35 million in government bonds.

After Bull Run, it was obvious that $35 million was a drop in the bucket compared to what was needed. More bonds were sold (about $3.4 billion by the war’s end), but Secretary of the Treasury Salmon Chase had another idea-an income tax. Congress passed a bill authorizing one, and the income tax became law on August 5, 1861. Version one imposed a flat tax of three percent on incomes over $800, or about $26,937 in 2022 dollars. This would be revised into a tier system in 1862, with a 3% tax rate on annual incomes between $600 and $10,000, and a 5% rate on incomes over that amount. (The 1862 law also created the “Office of the Commissioner of Internal Revenue”, the predecessor of the Internal Revenue Service.)

Not surprisingly, a lot of people didn’t like it, and many questioned whether it was even constitutional. Lincoln, his cabinet, and fellow Republicans argued that because it did not tax property directly, it was an “indirect” tax, and therefore not in violation of Article I, Section 9 of the Constitution, which says that direct taxes must be apportioned based on the population of each state. The Supreme Court agreed in 1864, and then the whole matter became moot when Congress repealed the income tax in 1871.

Then in 1894, Congress passed a new income tax. This time the Supreme Court decided it was a direct tax, and therefore unconstitutional.

So politicians changed the Constitution.

In 1909 Congress passed the 16th Amendment, which made levying an income tax legal. It was ratified by the states on February 3, 1913, and filling out our income tax forms has been an annual-and often excruciating-ritual ever since.