But on Monday, park officials announced the killer whale died after a possible pneumonia infection.
See also: California bans killer whale shows
The calf was the last orca to be born in captivity at a SeaWorld park.
Lori Marino, of the Whale Sanctuary Project, said: "What the death of this young calf tells us is that these animals cannot thrive in concrete tanks."
SeaWorld's orca program has been widely criticized after several high profile incidents involving its killer whales.
In 2010, a trainer was killed after being attacked in front of an audience in Orlando.
Attendance at SeaWorld parks has been falling amid bad publicity and criticism from animal rights activists.
Last year, the company announced it was suspending its captive breeding program and phasing out the killer whale shows at its three SeaWorld parks.
But activists say that doesn't do much for the 22 orcas that remain in captivity.