The U.S. Coast Guard Cutter Mackinaw traveled south from Cheboygan, Mich. , with the special mission to deliver 1,200 Christmas trees two weeks ahead of Christmas.
"This is something that we squeeze into our typical ACE-A Navigation mission every single year," said LTJG Carolyn Smith.
The Christmas Ship Committee was on hand to greet the ship and area school groups provided music.
WATCH: Christmas Tree Ship docks at Navy Pier
"It was so cool, I never seen anything like this," said Epiphany Catholic School student Kimberly Mercado.
The tradition dates back to the late 1800s. The original ship named the Rouse Simmons was a three-masted schooner that was easily recognized by the waiting crowds when they saw a Christmas tree tied to her main mast and her decks loaded with thousands of trees destined for Chicago families.
In 1912, the Christmas Tree Ship tradition halted after a fatal ship wreck. During that winter, 16 crew members died.
In addition to delivering this year's Christmas trees, the Crew of Mackinaw stopped to drop a wreath in Lake Michigan to honor the fallen crew members.
Captain Dave Truitt founded Chicago's Christmas Ship Committee, which restarted the beloved tradition 20 years ago.
"We believe that every kid should have a Christmas, and our story, as most of you know, is about bringing Christmas trees to kids who would not have Christmas trees," Truitt said.
On Saturday, all of those trees will be unloaded and passed out to families in need across the Chicago area.