On March 23, 2010, President Barack Obama signed the Affordable Health Care for America Act during a ceremony with fellow Democrats in the East Room of the White House. The polarizing law, dubbed "Obamacare" by many, is the signature legislation of Obama's time in office. The most controversial element of the new law required individuals not covered by insurance via their employer or the government to purchase and maintain minimal health insurance or pay a penalty. 
The constitutionality of the 2,409-page act has been challenged by a majority of states and numerous organizations. On January 31, 2011, Judge Roger Vinson declared the law unconstitutional in Florida v. United States Department of Health and Human Services, the first of many lawsuits challenging the constitutionality of the law. The act is currently being reviewed by the U.S. Supreme Court. 
The Supreme Court held three days of politically charged hearings in March on the 2010 Patient Protection and Affordable Care Act. 
Opponents of Obama's health care legislation protest in front of the Supreme Court in Washington on March 28. Many believe that the Constitution's Commerce Clause does not give government the authority to force Americans to purchase a commercial product, such as health insurance, they may not want or need. 
The positive effects of the law include reduced cost of seniors' medications and cheaper copays, according to reports. Here, advocates for universal, government-financed health care carry signs one month before the act was signed into law. 
Two years after President Obama signed the health care overhaul into law, the Supreme Court is taking up a historic test of whether it is valid under the country's Constitution. 
The Rev. Patrick Mahoney leads demonstrators in prayer outside the Supreme Court on June 25 as they await the court's ruling. According to a poll released Tuesday, 37% of Americans say they would be pleased if the health care law is deemed unconstitutional by the Supreme Court. 
Based on the hearings in March, the Supreme Court is expected to hand down its ruling on the health care reform Thursday. What the justices decide will have an immediate and long-term impact on all Americans, both in how they get medicine and health care and in vast areas of "commerce." - 49.9 million -- The number of uninsured Americans in 2010
- 15.4% - The percentage of children living in poverty who are also uninsured
- 95 million -- Number of people in the U.S. covered by government health insurance
(CNN) -- The Supreme Court is set to rule on the constitutionality of the Patient Protection and Affordable Care Act on Thursday. The landmark decision will dictate the way health care is administered to millions of Americans.
Here's a look at health care in the United States by the numbers, including the populations that could be most affected by the decision on what has come to be known as "Obamacare."
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49.9 million -- The number of uninsured Americans in 2010. That's 16.3% of the total population.
18.4% -- Percentage of uninsured Americans younger than 65 in 2010.
28.4% -- The percentage of Americans 25 to 34 without insurance.
7.3 million -- The number of children in the U.S. without health insurance, 9.8% of all children in the country.
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Health care law in grave trouble? 15.4% - The percentage of children living in poverty who are also uninsured.
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26.9% -- Percentage of people earning less than $25,000 a year who are also uninsured.
256.2 million -- The number of Americans who were insured in 2010.
195.9 million -- The number of Americans with private health insurance in 2010, 64% of the total population.
169.3 million -- The number of Americans who get their insurance through the workplace.
95 million -- Number of people in the U.S. covered by government health insurance, 31% of the population.
44.3 million -- Number of Americans receiving Medicare coverage in 2010.
48.6 million -- The number of Americans covered by Medicaid in 2010.
$940 billion -- The amount of money that the Congressional Budget Office estimates it will cost to provide the expanded insurance coverage over 10 years.
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$143 billion -- The amount by which the plan could reduce the deficit over the first 10 years. And over the following decade, the CBO projected, health reform could reduce the deficit by more than $1 trillion, although the agency stressed that such long-term projections are highly uncertain.
2.35% -- The tax rate high-income individuals would pay into Medicare, up from 1.45%. High-income is defined as individuals making more than $200,000 ($250,000 for couples filing jointly).
2014 -- The year that people who don't buy insurance will be penalized $95 or up to 1% in income.
19.1% - Percentage of people living in the South who are uninsured, the highest percentage of any region in the U.S.
24.6% - The percentage of uninsured people in Texas, the highest of any state.
5.6% - The percentage of uninsured people in Massachusetts, the lowest of any state.
