Untangling a family fortune that reaches back to the early days of the past century is murky business, but the annual federal financial disclosure reports Kennedy was required to file provide at least a' partial glimpse into his personal capital.
As a U.S. senator, Kennedy earned a base salary of $165,200 a year, but that just skimmed the surface of his net worth.
On the most recent report in 2008, which includes his own assets and those of his wife and any dependents, Kennedy listed a string of publicly and non-publicly traded trusts and assets. Under the filing rules, Kennedy was only required to place the value of those assets within a range, rather than give an exact dollar amount.
The report placed the net worth of his publicly traded assets somewhere between a low of $15 million and high of $72.6 million.
Just a year earlier, Kennedy reported somewhat rosier totals that placed his publicly traded assets somewhere between a low of $46.9 million and a high of $157 million.
Kennedy has other sources of income, including $1,995,833 in royalties he received from Grand Central Publishing a division of Hachette Group Book, publishers of his memoir True Compass scheduled for release in mid-September. Part of the proceeds will go to charity, including the John F. Kennedy Library.
Separate from his personal wealth was Kennedy's federal campaign account. As of the end of June, Kennedy reported more than $4.5 million in the account.
The main source of Kennedy's wealth was his father and family patriarch Joseph P. Kennedy who amassed a fortune in banking, real estate, liquor, films and Wall Street holdings that eventually grew to an estimated $500 million by the 1980s.
A significant portion of that came from Joseph P. Kennedy's decision to buy Chicago's famed Merchandise Mart in 1945 for $12.5 million. Spanning two city blocks and rising 25 stories, the sprawling limestone and terra-cotta mart is so large it has its own zip code and only lost its title as the world's largest building after the Pentagon was built in the 1940s.
The elder Kennedy helped transformed it into a national center for the home furnishings and design industries.
The family retained ownership of the building until 1998 when it was sold - along with other properties including Chicago's Apparel Center which covers about a million square feet - to Vornado Realty Trust of Saddle Brook, N.J. for $625 million in 1998 to take advantage of the then-booming real estate market.
The deal allowed Kennedy heirs to receive a stake in one of the nation's largest real estate investment trusts.
"One of my cousins reminded me of a quote from my grandfather: 'Only a fool waits for top dollar,'" Christopher Kennedy, the son of the late Sen. Robert Kennedy told The Wall Street Journal at the time.
The late John F. Kennedy Jr. also joked about his family's real estate holdings when he visited Chicago in 1996 to mark the launch of George magazine.
"In the 1940s, my family bought the Merchandise Mart. In the 1970s, we bought the Apparel Center. And in the 1960 election, my family bought 20,000 votes," he said, referring to his father's narrow presidential victory.
For Sen. Kennedy, the family fortune only reinforced his determination to expand access to health care.
It was a lesson he learned through his own painful experience.
In a Newsweek column he wrote a month before his death, Kennedy recalled the grueling treatment his son Teddy Jr. had to undergo in 1973 for bone cancer that eventually required the amputation of his right leg.
The experimental clinical trial, which included massive doses of chemotherapy, was free at first, but was deemed a success before some patients had completed their treatments. That forced some families to rely on insurance or pay out of pocket to cover the rest.
While Kennedy had the needed resources, not everyone was so lucky.
"Heartbroken parents pleaded with the doctors: What chance does my child have if I can only afford half of the prescribed treatments? Or two thirds? I've sold everything. I've mortgaged as much as possible," Kennedy wrote. "No parent should suffer that torment. Not in this country."