The couple, who asked to remain anonymous, formally adopted their daughter, whose name was also not released, on Wednesday -- a "gotcha day" that was celebrated in a post on Facebook by the Polk County Sheriff's Office.
"A happy ending that leads to a happy beginning," the sheriff's office captioned the post, in part.
Last January, sheriff's deputies replied to an emergency call in Mulberry, a small town about 30 miles outside of Tampa, reporting a newborn baby found on the side of the road.
According to the sheriff's office, the baby was just an hour old at the time and still had her placenta attached.
She was wrapped in a blanket and was found after a nearby resident heard her crying, authorities said.
The baby was taken to a nearby hospital, where she was found to be "healthy and stable," authorities said at the time.
The then-newborn was taken into the custody of the Florida Department of Children and Families while authorities searched for her mother, who was never found, according to authorities.
On Wednesday, 10 months and one day after her birth, the baby was formally adopted.
Photos shared by the sheriff's office show the girl dressed in a pink dress and pink shoes, with her hair done in pigtails for her adoption day.
Florida has a safe haven law that allows parents to leave a newborn child under 1 week of age at a state-approved hospital, emergency medical services station or fire station without fear of prosecution.
Currently, safe haven laws exist in all 50 states, but age limits vary as to when a newborn can be placed in a baby box, according to the U.S. Department of Health and Human Services.