What distinction did Metallica's 1991 album, The Black Album, achieve on the Billboard 200?

The Black Album became Metallica's first album to reach number one on the Billboard 200.

It debuted at the top of the US album chart after selling about 598,000 copies in its first week. The achievement was especially significant because the band's previous four studio albums had established a major metal following without topping the main US albums chart.

The album remained at number one for four consecutive weeks. Its chart success reflected both the strength of the singles and the group's broadened sound, which retained heavy guitars while using more direct arrangements and memorable melodies.

The Black Album's Billboard performance helped make Metallica one of the world's most commercially successful metal acts. It also became a long-running catalog seller, continuing to appear on the chart many years after its original release.