In the early morning hours of March 4, 1801, John Adams, the second president of the United States, quietly left Washington, D.C. under cover of darkness. He would not attend the inauguration ceremony held later that day for his former friend—now political rival—Thomas Jefferson, who would soon replace Adams in the still-unfinished presidential mansion.

On the heels of his humiliating defeat in the previous year’s election, Adams was setting an important precedent. His departure from office marked the first peaceful transfer of power between political opponents in the United States, now viewed as a hallmark of the nation’s democracy.

The U.S. Constitution left out the mention of political parties, as many founders viewed “factions” as a danger to democracy. “The common and continual mischiefs of the spirit of party are sufficient to make it the interest and duty of a wise people to discourage and restrain it,” George Washington famously declared in 1796, after making the momentous decision to step aside after two terms as the nation’s first president.

But the spirit of party already existed in the United States—even within Washington’s own cabinet. As the nation’s first secretary of state, Jefferson clashed repeatedly with Alexander Hamilton, the treasury secretary, over the growing power of the federal government, which Jefferson distrusted. In 1791, Jefferson and James Madison formed the Democratic-Republican Party in opposition to Hamilton’s ambitious Federalist programs, including a new national banking system.

In the election of 1796, Jefferson and Adams, Washington’s vice president, competed to succeed him, with Adams pulling off a narrow victory. Because the Constitution hadn’t provided for political parties, the system of electing the president didn’t take them into account: The candidate who got the most votes (Adams) became president, and the runner-up (Jefferson) became vice president.

During Adams’s presidency, Democratic-Republicans and Federalists clashed over everything from taxes to religion, but especially over the main policy dilemma facing the nation: how to deal with the ongoing French Revolution. Jefferson and his supporters favored an alliance with France, while Adams and the Federalists leaned toward a stronger relationship with Great Britain, and tried to exert control by passing the controversial Alien and Sedition Acts, which allowed Adams to imprison those who spoke out against him.

These bitter differences were front and center during the 1800 presidential campaign, which played out in the highly partisan press. Federalist newspapers and propaganda materials branded French sympathizers as dangerous radicals, while Democratic-Republicans accused the Federalists of wanting to reestablish a monarchy.

Meanwhile, the Federalists were divided amongst themselves: Hamilton attacked Adams in print, and even masterminded a failed plan to get Federalists to vote for his running mate, Charles Cotesworth Pinckney.

When the votes were counted, confusion reigned. Though Jefferson and his running mate, Aaron Burr, had defeated Adams and Pinckney, both had received the same number of electoral votes. The tie sent the decision to the House of Representatives, where Jefferson finally won the presidency on the 36th ballot. (The 12th Amendment, ratified in 1804, would mandate that electors vote separately for president and vice president, avoiding similar chaos in future.)

Before he left office, Adams made a number of Federalist judicial appointments—including installing John Marshall as chief justice of the Supreme Court, which Adams later called the “proudest act” of his life. Then, for reasons that he never made public, he chose to skip Jefferson’s inauguration, leaving on the early morning stagecoach out of Washington that morning to begin the journey back to his beloved Quincy, Massachusetts.

Since 1801, the peaceful transfer of power has remained a hallmark of U.S. government, joining the two-party system as key aspects of ensuring a healthy democracy.

Adams’s early-morning departure aside, a majority of outgoing presidents have attended the inaugurations of their successors. Notable exceptions include Adams’s own son, John Quincy Adams, who declined to attend Andrew Jackson’s first inaugural in 1829; and the embattled Andrew Johnson, who refused to attend the inauguration of Ulysses S. Grant as his successor in 1869, choosing to hold a final meeting of his cabinet instead.

Inaugural customs for outgoing presidents have changed over the years, according to the Joint Congressional Committee on Inaugural Ceremonies. In 1837, Jackson and his successor, Martin Van Buren, began a new tradition by riding together to Van Buren’s inauguration at the U.S. Capitol.

Until the early 20th century, the outgoing and incoming presidents additionally rode together back to the White House after the inaugural ceremonies. Theodore Roosevelt was the first to depart from this pattern in 1909 by heading directly from the Capitol to Union Station, where he caught a train to New York.

Later presidents, such as Harry Truman, Dwight D. Eisenhower and Lyndon B. Johnson, left the Capitol grounds by car. Since Gerald Ford’s departure from office in 1977, most outgoing presidents and first ladies have departed the inaugural ceremonies via helicopter, leaving their successors to attend an inaugural luncheon inside the Capitol building.