Social Security is hands-down our nation's most important social program. Today, more than 62 million people are receiving a monthly benefit, with an estimated 22.1 million of those folks being kept above the federal poverty level as a result of their monthly stipend. No other social program can lay claim to improving the financial well-being of Americans like Social Security.

However, the program we know today has been reshaped many times over since its inception in 1935. Each of these changes has come from Capitol Hill and, in many cases, with the backing of the president of the United States. Since the Social Security Act was signed into law on Aug. 14, 1935, 14 presidents have overseen the program. Here's a list of each of their biggest contributions to Social Security.

A person tightly grasping their Social Security card with their thumb and index finger.

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Franklin D. Roosevelt (1933-1945)

Roosevelt played the most important role of all the listed presidents in being the architect behind the Social Security Act, which provided financial protection for older Americans who could no longer earn a wage after decades of employment. Though the bill was signed into law in August 1935, payouts didn't actually begin until Jan. 1, 1940. That's because, beginning on Jan. 1, 1937, workers would begin paying into the system and accruing lifetime work credits. The money collected prior to 1940 was used to help cover benefits for eligible workers aged 65 and older beginning Jan. 1, 1940.

It's worth pointing out that Roosevelt also oversaw the expansion of Social Security benefits to dependents and survivors of deceased workers.

Harry S. Truman (1945-1953)

Truman will likely be best remembered for introducing the first annual cost-of-living adjustment, or COLA. To be clear, this isn't the same COLA that we're used to today, as measured by the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W). Rather, any inflationary increase in payouts for the program needed to be enacted through Congress. In September 1950, beneficiaries received a 77% increase to their payout, which was followed by another 12.5% increase in September 1952. Or, put in another context, Social Security benefits nearly doubled (+99.1%) under Truman's presidency. 

Dwight D. Eisenhower (1953-1961)

Although more than 10 million people receive benefits from Social Security's Disability Income Trust today, disability benefits weren't a part of the original bill. It was Dwight Eisenhower who signed the Amendments of 1956 into law to provide monthly benefits to permanently disabled workers between the ages of 50 and 64, as well as to adult children of deceased workers who were disabled prior to age 18. If not for Eisenhower, these disability protections would not exist today.

A person filling out a Social Security benefits application form.

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John F. Kennedy (1961-1963)

Even though Kennedy's presidency was tragically cut short, he still left a lasting impression on the Social Security program. In June 1961, just five months after taking office, he signed the Amendments of 1961 into law. The biggest change associated with this new law was it allowed workers the option to claim their benefits as early as age 62 (previously it was age 65). Of course, if workers choose to claim their benefits early, they'll receive a reduced monthly payout. Today, more than half of all beneficiaries claim their benefit before reaching full retirement age.

Lyndon B. Johnson (1963-1969)

Lyndon Johnson is probably best known for signing the Medicare bill into law, which now rivals Social Security in terms of eligible beneficiaries. Eligible workers aged 65 and up can qualify for Medicare benefits. Though Medicare is designed to protect seniors from the high costs associated with medical care, the Social Security Administration was the agency put in charge of administering the program.

Richard Nixon (1969-1974)

Most folks might associate President Nixon with the Watergate scandal of 1972, but they may not realize he's the president responsible for making COLAs automatic on an annual basis. On July 1, 1972, Nixon authorized the Social Security Administration to use the CPI-W as its inflationary tether for the program and, beginning in 1975, administer inflation-based "raises" in accordance with changes in the CPI-W. In 2019, beneficiaries will receive a 2.8% "raise" based on the law Nixon passed in 1972.

Additionally, it's worth mentioning that Nixon was responsible for the creation of Supplemental Security Income, or SSI.

A judge's gavel lying atop two Social Security cards, and in front of an American flag.

Image source: Getty Images.

Gerald Ford (1974-1977)

Interesting enough, it's not what Ford did, but what he didn't do that's most memorable. In 1974, President Ford vetoed H.R. 15301, which was a bill designed to finance a deficit for the Railroad Retirement system. Ford believed the burden on taxpayers ($285 million a year for 25 years) to cover the $7 billion deficit was simply too great. What's notable is that Congress overrode the president's veto, making this bill a law, and marking the first time lawmakers in Washington were able to override a Ford veto. 

Jimmy Carter (1977-1981)

When it comes to Social Security, Carter will be best known for signing the Amendment of 1977 into law. With the program facing an exhaustion of its asset reserves by 1979, per the 1975 Trustees report, the Amendments of 1977 "raised the payroll tax slightly (from 6.45% to the current 7.65%), increased the wage base, reduced benefits slightly, and decoupled the wage adjustment from the COLA adjustment," according to the Social Security Administration. Despite Carter's efforts, more changes would be needed to sustain the program just a handful of years later. 

Ronald Reagan (1981-1989)

The last major overhaul of Social Security occurred under Reagan's watch with the passage of the Amendments of 1983. The two biggest changes included the introduction of the taxation of benefits for those recipients earning over select income thresholds and, secondly, the gradual increase of the full retirement age from 65 to 67 between 1983 and 2022. These changes were designed to bring in additional revenue (up to half of a person's or couple's benefits were subject to federal income tax), as well as limit lifetime benefit payouts to future generations.

A golden key lying atop two Social Security cards.

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George H. W. Bush (1989-1993)

Under George H.W. Bush, the single-most memorable moment was the signing of the Omnibus Budget Reconciliation Act (OBRA) on Dec. 19, 1989. OBRA contained 25 separate provisions related to Social Security, which included the requirement that the Social Security Administration send personal earning and benefit statements to persons working under Social Security. These statements allow workers to estimate what they'll receive from the program if claiming at full retirement age. 

Bill Clinton (1993-2001)

Of all the presidents, Clinton's most important contribution is the toughest to decide -- so I'm calling it a tie. Under Clinton, a second tier was introduced under the taxation of Social Security benefits that allowed up to 85% of an individual's or couple's benefits to face federal income taxation. Additionally, Clinton also oversaw the elimination of the retirement earnings test for those who've reached or surpassed their full retirement age. In other words, it disallowed the Social Security Administration from withholding benefits based on a person's earning capacity.

George W. Bush (2001-2009)

Like Gerald Ford, the younger Bush is known best for what he didn't do, rather than what he did do for Social Security. In February 2005, shortly after his reelection to a second term, George W. Bush pushed for the partial privatization of Social Security. Doing so would have placed a portion of a worker's earnings into a separate retirement account that they could invest as they saw fit. While it sounded great on paper, privatization of any form was a problem because the American public isn't very investment-savvy. Additionally, it did nothing to resolve the program's long-term cash shortfall. The failure of Bush's proposal to gain traction took a long-standing idea off the table for good, most likely.

A long hallway in a prison with a row of cells to the left.

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Barack Obama (2009-2017)

As has been the theme since the year 2000, things have been quiet on the legislative front for Social Security. Under the Obama administration, arguably the biggest change occurred in December 2009, when H.R. 4218 disallowed prisoners, parole violators, of those fleeing from prosecution where the punishable sentence is more than one year, from receiving Social Security benefits. It's almost hard to believe that no such law was on the books prior to this.

Donald Trump (2017-present)

Last but not least, current President Donald Trump's impact can best be felt through the passage of the Tax Cuts and Jobs Act (TCJA) in December 2017. The TCJA, as the name implies, is designed to create jobs and stimulate U.S. economic growth via corporate and individual tax cuts. Presumably, if job and wage growth remain strong, payroll tax revenue may come in above expectations, thereby improving the short-term outlook for the program. Whether this proves to be the case remains to be seen.