President Franklin Roosevelt signs into law the Social Security Act, originally designed to provide economic security during the Great Depression.

The 1935 act offers aid for the unemployed, the elderly and children, as well as for various state health and welfare programs. It also creates a system to provide financial benefits to retired workers in commerce or industry, except railroad workers, aged 65 or older.

President Roosevelt appoints a three-member, bipartisan Social Security Board to run the program. (Over the years, Social Security is modified to concentrate on retirement and disability insurance, and the other aid programs are disbursed to other federal agencies.)

According to the 1935 law, the system is financed through payroll taxes -- a tax that becomes the Federal Insurance Contribution Act, or FICA, in 1939. These payroll taxes start out at 2 percent.

The U.S. Postal Service begins distributing applications for Social Security account numbers. The lowest number, 001-01-0001, goes to Grace Dorothy Owen of Concord, N.H.

Over the next year (1937), the Postal Service issues more than 35 million SSN cards.

Retired Cleveland motorman Ernest Ackerman receives 17 cents as a one-time, lump sum Social Security payment. At the time, the average payment was $58.

Under the Federal Reorganization Act, the Social Security Board becomes part of the newly established Federal Security Agency, losing its status as an independent agency.

New amendments expand Social Security to include benefits for the families of deceased workers and for retirees' dependents, such as children and spouses. The bill also replaces lump-sum payments with a monthly payment system and creates a separate trust fund for Social Security payroll tax income.

Ida May Fuller, a retired legal secretary, receives the first monthly retirement check for $22.54. Some 222,400 people receive Social Security benefits in 1940.

President Harry Truman's Reorganization Plan renames the Social Security Board as the Social Security Administration.

President Truman signs the 1950 Social Security Amendments, which in part enact the very first "cost-of-living-adjustment" (COLA) to offset the effects of inflation on fixed Social Security incomes. This first COLA applies a 77 percent increase to Social Security benefits.

All future COLA increases, which would be much lower than the first, require special approval from Congress.

President Dwight Eisenhower's Reorganization Act abolishes the Federal Security Agency and moves the SSA to the newly created, Cabinet-level Department of Health, Education and Welfare, or the future Department of Health and Human Services.

New legislative reforms add benefits for permanently and totally disabled workers aged 50 to 64.

President John Kennedy approves new amendments, which in part allow male workers to choose reduced retirement benefits at 62. Women received the early retirement option in 1956.

In 1960, more than 14.8 million people receive Social Security benefits -- a substantial jump from some 3.5 million beneficiaries a decade earlier.

President Lyndon Johnson signs the Medicare bill, which extends health coverage to Social Security beneficiaries 65 years or older. The SSA would oversee the Medicare program until the government reorganizes these agencies in 1977.

President Richard Nixon signs a new COLA bill authorizing a 20 percent increase to benefits. More importantly, the bill requires automatic COLAs each year to keep up with inflation, which go into effect in 1975.

The 1972 bill also adds the Supplemental Security Income program, a needs-based program for elderly, blind, or disabled persons, which officially becomes part of the SSA in 1974.

Payroll taxes, including those for Social Security, total 9.2 percent.

Medicare and Medicaid are moved from Social Security oversight to a new Health Care Financing Administration.

President Jimmy Carter signs new amendments, which in part seek to limit the cost of disability insurance and require the SSA to review regularly the disability status of beneficiaries. These controversial reviews become very unpopular and end under a 1984 legislative reform.

More than 35 million people receive Social Security benefits payments in 1980. This substantial growth takes a toll on the program -- the trust fund reserves hold $26 billion, a steep drop from $46 billion in 1974.

The Omnibus Budget Reconciliation Act cuts some benefits, largely by eliminating student benefits and limiting lump-sum death payments.

To ward off a short-term financial crisis, Congress authorizes borrowing from the three Social Security trust funds -- Old Age and Survivors Insurance, Disability Insurance and Medicare Hospital Insurance. The SSA borrows from these funds twice in 1982 and repays the loans within four years.

President Ronald Reagan and Congress create the National Commission on Social Security -- known as the Greenspan Commission after its chairman Alan Greenspan -- to study the program's financial problems and make recommendations for legislative reforms.

President Reagan signs the 1983 Social Security Amendments, which incorporate many of the Greenspan Commission's recommendations.

Those recommendations include an increase in the self-employment tax, the partial taxation of Social Security benefits to wealthier retirees, coverage of all federal employees and a gradual increase of the retirement age from 65 to 67, starting in 2000. The bill also augments the reserves in the Social Security trust funds and accelerates the scheduled increases of Social Security tax rates.

Payroll taxes reach 11.4 percent.

The Social Security Administration becomes an independent agency.

President Clinton signs a welfare reform bill, which rules out benefit eligibility if alcoholism or drug addition play a role in the disability.

President Clinton approves the Senior Citizens' Freedom to Work Act of 2000, eliminating the Retirement Earnings Test for those beneficiaries at or above normal retirement age of 66. This change allows for some 900,000 beneficiaries, who continue to work, to receive full benefits instead of having them reduced based on earnings.

The Social Security Board of Trustees projects that the program will remain solvent until 2038.

President George W. Bush appoints a bipartisan, 16-member commission to study ways to improve Social Security's long-term fiscal health with individually controlled, voluntary personal retirement accounts.

The President's Commission to Strengthen Social Security -- also known as the Moynihan Commission after its co-chairman, the late Sen. Daniel Patrick Moynihan, D-N.Y. -- releases its final report to Congress.

The Social Security Board of Trustees in its annual report determines that Social Security is not sustainable for future generations unless the program changes.

President Bush calls on Congress to "confront the [Social Security] problems now" and urges the creation of individual retirement accounts. The president describes Social Security reform as one of the top agenda items for his second term.

-- Compiled by Liz Harper for the Online NewsHour