Where did that doggone phrase come from?

When did "my dog ate my homework" become known as schoolchildren's favorite excuse?

The 1970s.

Delinquent schoolchildren and adults have been blaming their shortcomings on their pets for more than a century, but it wasn't until the 1970s that "my dog ate my homework" came to be considered the No. 1 likely story.

One of the first sad sacks who was said to blame his dog for his own ill-preparedness was a priest. In this anecdote, which appeared as early as 1905, a clergyman pulls his clerk aside after a service to ask him whether his sermon seemed long enough. The clerk assures him that it was very nice, "just the right length," and the priest is relieved. "I am very glad to hear you say that," he says, "because just before I started to come here my dog got hold of my sermon and ate some of the leaves." The story was repeated again and again.

The first citation of the excuse in the Oxford English Dictionary is a 1929 article from the Manchester Guardian, which reads, "It is a long time since I have had the excuse about the dog tearing up the arithmetic homework." In Bel Kaufman's best-selling 1965 novel "Up the Down Staircase," a list of students' excuses for not having their homework includes "My dog went on my homework" and "My dog chewed it up." Even in 1965, however, it was still just another excuse.

"My dog ate my homework" became known as the quintessential far-fetched excuse in the next decade, when the phrase was used over and over. In a 1976 account of the Watergate tapes, E.C. Kennedy describes listening to President Richard Nixon "working on the greatest American excuse since the dog ate my homework." A 1977 article from Alaska's Daily News-Miner describes the difficulty students faced in coming up with a new excuse since "'My dog ate my term paper' is no longer acceptable."

The excuse was alluded to more throughout the 1980s. A 1982 Time magazine column on excuses suggested that "the dog ate my homework is a favorite with schoolchildren," while a 1987 New York Times column about how students were starting to blame malfunctioning computers and printers quoted one teacher as saying she recently received "a note from a student's mother saying the dog ate his homework."

Even the president picked up on the trend: When Congress pushed spending approval to the last minute in 1988, Ronald Reagan complained to reporters, "I had hoped that we had marked the end of the 'dog-ate-my-homework' era of congressional budgetry ... but it was not to be." After that, the phrase was all over television, including shows such as "The Simpsons" and "Full House."

Between 1990 and 2000, the phrase continued to grow in popularity. The New York Times wrote articles with headlines such as "Beyond 'Dog Ate My Homework' " and "Homework Help Sites (Or, the Dog Ate My U.R.L.)." The New Yorker described one criminal's accounts of his wrongdoings as having "a decided my-dog-ate-my-homework quality."

Not to be outdone, children's books tried to capitalize on the trend, with titles like "A Dinosaur Ate My Homework," "Aliens Ate My Homework," "Godzilla Ate My Homework" and even "My Teacher Ate My Homework."

While such book titles have continued into the 2000s, the phrase seems to finally be losing steam.

That means schoolkids will have to come up with a new, improved excuse.