George Bush lamented in 1993 that “losing is never easy — trust me, I know,” after losing to Bill Clinton. Gerald Ford in 1977 allowed for the possibility of a political comeback after being defeated by Jimmy Carter (“This report will be my last — maybe.”) Donald J. Trump was defiant in defeat four years ago, declaring that “we will be back in some form.”

As far back as the 18th century — when George Washington warned the young republic of the dangers of partisanship and called for national unity — presidents have used their twilight days in office to reflect on their records and accomplishments, pleading for the nation to build on their legacies for generations to come.

That parting message has been at times complicated by the outgoing commander in chief being succeeded by a political rival — especially when being beaten out of a second term.

The challenge President Biden navigated Wednesday night was similarly delicate, as he highlight his achievements and reflected on America’s future — even as he hands the reins of government over to Mr. Trump, an adversary whom Mr. Biden has declared a threat to democracy, and who has vowed to undo many of his policies.

Here’s how some single-term presidents approached their farewell speeches:

Lyndon B. Johnson urged Congress to protect his legacy.

President Lyndon B. Johnson left office in a remarkably similar position to Mr. Biden: Shadowed by contentious foreign wars, and struggling to hammer out a peace agreement with an adversary, Johnson ended his re-election campaign and cleared the way for his vice president, Hubert Humphrey, to be chosen as the Democratic presidential candidate at the party convention in Chicago. (Humphrey was ultimately defeated by Richard Nixon after struggling to distinguish himself from Johnson.)