In 1973, at the time of his retirement, former Baltimore Colts quarterback Johnny Unitas held most of the NFL's major passing records. Although some of those have since been broken, there is one that may never fall.

When Unitas threw a touchdown pass against the Los Angeles Rams on Dec. 9, 1956, it marked the first of 47 straight games in which he would have at least one scoring strike. It's a record that's been likened to Joe DiMaggio's 56-game hitting streak.

Not bad for a quarterback who had been playing semi-pro football the year before the streak began.

Unitas was a ninth-round draft pick by the Pittsburgh Steelers out of the University of Louisville in 1955. In a move that will forever cause Steelers fans to cringe, the Steelers cut the future Hall of Famer before the season began. Unitas never even played in a preseason game for Pittsburgh, playing semi-pro ball during 1955 instead. He was signed by Baltimore the following year during training camp, made his debut in the Colts' fourth game of the 1956 season when starting quarterback George Shaw broke his kneecap. Unitas would go on to become one of the top quarterbacks in the history of the game and establish himself as an icon in Baltimore. Unitas' touchdown streak was going strong in 1958 when he helped change the way the NFL was viewed around the country.

Despite missing a few games during the regular season with three broken ribs, Unitas returned in time to help the Colts clinch the Western Conference crown, but it was in the NFL Championship game against the New York Giants that he really made his mark.

... the Colts trailed 17-14 with less than two minutes remaining in the fourth quarter when Unitas started to work his magic. The Colts started with the ball on their own 14 and 1:56 to play. Things looked bleak when Unitas threw two incompletions. But on third-and-10 he hit Lenny Moore for an 11-yard gain and a first down. Then came gains of 25, 16 and 21 yards on three passes to Raymond Berry. Unitas marched the Colts down to the Giants 13 when kicker Steve Myhra was summoned. Myhra nailed a 20-yard field goal to tie the game. What happened next was an NFL first - sudden death in a postseason contest. Never before had an overtime game been played during the playoffs. The television audience was so enthralled with what it saw that the NFL was catapulted into a new stratosphere.

And at the center of it was Unitas.

He led the Colts on a 12-play scoring drive in overtime, capped by a one-yard Alan Ameche run, as Baltimore captured the NFL Championship. Unitas continued delivering touchdown passes in 1959 as he led the Colts to their second straight NFL title.

The streak would come to an end in 1960, against the Rams, against whom Unitas began the streak four years earlier. The closest anyone has come to duplicating the feat was Miami Dolphins great Dan Marino, who put together a 30-game streak in the 1980's.

Unitas ended his career in 1973 with the San Diego Chargers. He finished with 2,830 completions for 40,239 yards and 290 touchdowns. Though Unitas played his final game more than 25 years ago, his legendary accomplishments and popularity with fans and collectors is still evident. HBO recently produced a documentary profiling "Number 19," and his cards are among the most sought-after by vintage football card collectors.

Unitas' 1957 Topps rookie is listed at $5,000 for a Mint 9 in the February issue of the Sportscard Market Report, the highest priced card in the set. His 1958 Topps card is second only to Jim Brown's rookie at $1,425 for a Mint 9.