Hemp fiber was one of the primary things archaeologists found this week when they examined remains from a ship that sunk sometime during the 1800s.

The sunken ship was accidentally discovered by a construction crew working in Boston.

While digging at the site, the team noticed something unusual buried in the Seaport District of Boston.

They immediately stopped working and called in experts.

It turns out that what they found was a 50-foot long ship from the mid- to late-19th century that had somehow sunk. As the city continued to grow over the years, the ship had been buried and forgotten.

“Nothing like this has been found in Boston, in the filled-in ground, before,” said City of Boston archeologist Joe Bagley.

“This is incredibly rare and incredibly amazing.”

Experts think the ship was used to haul lime.

Back in the 1800s lime was used to make paper and in various construction projects.

But lime could also be the reason the ship sunk. That’s because when lime comes into contact with water it can sometimes cause fires.

Archeologists who were excavating the shipwreck were excited to discover that there was still cargo on board.

So far they’ve dug up a fork, a stack of dishes, remains of barrels, hemp fiber, and more.

Hemp was a big time commodity back in the 1800s. It was one of the most common crops grown in America from the 1600s through the 1800s.

In fact, in 1619 the Virginia Assembly passed a law that required every farmer in the colony to grow hemp.

The plant’s fibers were used to make cloth, ropes, sails, and more.

There was even a time when hemp could be used as money in certain American colonies.

And historians say the first American flags were made out of hemp that was grown by important founding figures like George Washington and Thomas Jefferson.

The U.S. continued growing hemp and producing hemp fiber textiles until roughly the start of the 1900s.

But when cannabis became illegal, so did hemp, although it’s technically a type of cannabis that doesn’t have any psychoactive effects.

The shipwreck discovered this week in Boston is giving archaeologists a glimpse into what American life was like in the 1800s. And hemp fiber was a vital part of that life.