The closures follow a collapse in Atlantic City's gambling revenue to $2.86 billion last year from a peak of $5.17 billion in 2006, the year Pennsylvania's first casinos opened, allowing many former Atlantic City regulars to gamble closer to home. New York and Maryland soon opened their own casinos, diverting even more gamblers from Atlantic City.
Closing day was rough on Showboat's 2,100 employees, though more than 470 of them had been offered jobs at other Caesars casinos.
"I was surprised I got so emotional" saying goodbye to colleagues, Brian Klinger, 61, a Showboat games supervisor, said as he was leaving the casino floor for the last time.
"A lot of these people I'll probably never see again, unless it's by chance," said Klinger, who has worked in Atlantic City casinos for 32 years, the last 10 at Showboat.
Klinger was offered a part-time position at another Caesars property but turned it down because he wants to work full time in the casino-support industry.
Josie Anzisi, who has worked at Showboat's House of Blues since it opened in 2005, has deep roots in the Atlantic City casino industry.
Her father worked at Resorts International when it opened as the city's first casino in 1979. "I remember going there when I was little and playing on the piano and doing my homework in the ballroom," Anzisi said.
Anzisi has worked in the casinos since she was 18, at Bally's, Resorts, and then Showboat.
She said Showboat was her favorite. "It's the strongest family, as far as casino families go," she said.
But now, it's time for a change. Her whole family will be out of work soon, Anzisi said. Her son works at Showboat and Revel, and her husband works at Trump. They plan to move to Florida in October, she said.
Loyal customers have helped Showboat win $8.5 billion from gamblers since it opened in March 1987 as Atlantic City's 12th casino.
When Showboat Inc. opened its casino, it was known as a company that specialized in appealing to low rollers. It promoted bowling as a family-friendly activity to go along with a casino floor that heavily emphasized slot machines.
Those child-friendly features attracted Gabrielle Cataldi's family.
"I started coming here when I was 4," Cataldi, 31, of Nesco, N.J., said Sunday while walking through Showboat with her mother, husband, and son.
Since then, she has celebrated her birthday there every year.
In addition to bowling, there was an arcade and all kinds of games for little children, said Marie Cataldi, Gabrielle's mother, who would spend time on the second floor with her daughter while her husband, Joseph, gambled on the first floor.
Aside from visits with Gabrielle - including a birthday trip every year - Joseph and Marie Cataldi used to be at Showboat every Thursday, but always "home in time to meet the school bus," Marie Cataldi said.
Showboat was bought by Harrah's Entertainment Inc. in 1998 and eventually became part of Caesar's Entertainment. The bowling lanes closed in 2001 to make room for more restaurants.
Showboat distinguished itself in 1999 by building an 800-car parking garage for employees, the first in Atlantic City.
Adding to the disappointment Sunday was an earlier-than-anticipated closing. The casino stopped letting people in at 3 p.m., despite the announced closing time of 4 p.m., annoying patrons who spent the day at the beach and were told, as they approached Showboat's boardwalk entrance, that they couldn't walk through the property to get to their cars.
The early closing was to ensure the casino floor could be cleared of gamblers by 4 p.m., employees said.
Security guards in yellow shirts dashed the hopes of many others who wanted to sneak in for a quick visit in the last hour.
Among the disappointed were John Paxton Jr. and Jason Lantz, two Atlantic City natives who said they became friends while they were interns at Showboat in the late 1990s. Both said they had college scholarships from Showboat.
"We came just to walk though one last time," said Paxton, 38, who works in academic support services for athletes at Rutgers University.
"This place gave me what I call a cornerstone," Paxton said.