MercyMe's "I Can Only Imagine" has become Oklahoma's official inspirational song after Governor Mary Fallin signed it into law on April 19.

The governor and representatives of both the House and Senate floors unanimously agreed that "I Can Only Imagine" would be the state's inspirational song. Deliberations for HB 3473, which was proposed in February, was fast tracked into law after just two months.

MercyMe established their roots in an abandoned daycare center in Oklahoma City over two decades ago. Lead singer Bart Millard transformed the site into a studio where he would rehearse with guitarist Mike Scheuchzer and pianist Jim Bryson. Bassist Nathan Cochran, drummer Robby Shaffer and guitarist Barry Graul would later complete the band.

In 1999, they released "I Can Only Imagine," which Millard wrote and the band recorded in their makeshift studio for their album "The Worship Project." The song was subsequently re-released in 2001 for their "Almost There" album.

"I Can Only Imagine" would spend more than 30 weeks in the Billboard charts and would emerge as the best-selling Christian song of all time. Last March, the "I Can Only Imagine" movie based on the hit song smashed box office expectations, taking in close to $80m.

The film inspired Oklahoma Rep. Randy McDaniel to file the bill proposing that the state adopt "I Can Only Imagine" as its inspirational song. The representative told Tulsa World, "Seeing the film inspired me to take action to give this extraordinary song official state recognition and a permanent home in Oklahoma's musical landscape."

The state also recognized the contribution of "I Can Only Imagine" to the Oklahoma Film and Music Office. Its success provided jobs for the locals for 270 days during the movie's production.

The signed legislation will be presented to MercyMe during a concert at the Frontier City on Saturday, June 9.