The life-saving practice of organ transplantation has come a long way over the centuries. Today, more than 30,000 kidney, heart, lung, and other organ transplants happen each year. In honor of National Donor Day, here are a few facts about the history and the current practice of organ donation.

1. THE FIRST ORGAN TRANSPLANT TOOK PLACE IN 800 BCE.

Skin, the body’s largest organ, was also the first to be transplanted. Researchers have found evidence that Indian doctors pioneered the use of skin grafts to repair injuries. In 500 BCE, a doctor named Sushruta performed the first rhinoplasty procedure by taking skin from a patient’s forehead and transplanting it to the nose.

2. A 16TH CENTURY ITALIAN SURGEON DISCOVERED ORGAN REJECTION.

by Gaspare Tagliacozzi // scanned by Google [Public domain], via Wikimedia Commons

Gaspare Tagliacozzi, a renowned physician at the University of Bologna, further refined Sushruta’s rhinoplasty procedure, refashioning the noses of maimed soldiers using skin from the inside of the arm. He also developed procedures to repair lips and ears using transplanted skin from a person’s own body. But when Tagliacozzi tried to graft skin from a different donor, the body would reject the transplant. His notes on organ rejection marked an early recognition of a problem that would stymie organ transplants for centuries to come.

3. IN THE EARLY 20TH CENTURY, DOCTORS TRANSPLANTED ANIMAL ORGANS TO HUMANS.

Going back as far as the 17th century, doctors transfused animal blood into humans. In the 19th century, animal-human skin grafts were quite popular, with frogs being the preferred species. By the 20th century, physicians were transplanting parts from rabbits, pigs, dogs, and other animals into human patients, none of whom lived more than a few days following their operations.

4. THE FIRST CORNEAL TRANSPLANT HAPPENED IN 1905.

Modern physicians still marvel at the procedure, undertaken by Austrian ophthalmologist Eduard Zirm. Using corneas taken from a child donor, Zirm successfully grafted them onto a 45-year-old farmworker, who had lost most of his eyesight in an accident. Zirm’s success is credited to sanitary conditions that were ahead of their time, and ophthalmologists today still use techniques that evolved from his original procedure.

5. CHARLES LINDBERGH CONTRIBUTED TO ORGAN TRANSPLANT TECHNOLOGY.

Known as a daring flyer, Lindbergh was also an accomplished mechanic who thrilled to an engineering challenge. After working for several years with transplant pioneer Dr. Alexis Carrel, in 1935 the two unveiled the perfusion pump, an intricate glass mechanism that could preserve organs outside the body. The invention landed the duo on the cover of Time magazine, though it ultimately proved too unreliable for physicians.

6. THE FIRST SUCCESSFUL KIDNEY TRANSPLANT TOOK PLACE IN 1954.

The Herrick brothers with their team of doctors. Wikimedia Commons

In the days before immunosuppressant drugs, transferred organs were almost uniformly rejected by their recipients. Then, in 1954, doctors in Boston were presented with an interesting case: Ronald Herrick, 23, had agreed to donate one of his kidneys to his identical twin brother, Richard, who was dying of kidney failure. The transplant was a success, with Richard living eight more years—far beyond the point anyone who had previously received a transplanted kidney had lived. Ronald, meanwhile, lived 56 more years, passing away in 2010.

7. IMMUNOSUPPRESSIVE DRUGS CHANGED THE GAME.

In 1960, immunologists Sir Frank Macfarlane Burnet and Peter Medawar won the Nobel Prize for their work studying immunosuppression and organ transplant failure. This opened the door to the development of immunosuppressive drugs, which allowed doctors to transplant organs from non-identical donors. The next decade would see the world’s first successful lung, liver, pancreas, and heart transplants.

8. KIDNEYS ARE THE MOST COMMONLY TRANSPLANTED ORGAN.

More than 17,000 kidney transplants happen every year in America, according to the National Kidney Foundation, comprising more than half of all organ donations. After decades of developments, including better immunosuppressive drugs, kidney transplants are one of the most effective transplant procedures being practiced today. And yet, the donation rate only puts a dent in the more than 100,000 people waiting for kidney transplants each year.

9. DEMAND FOR DONATIONS GREATLY EXCEEDS SUPPLY.

Between 1991 and 2015, according to the U.S. Department of Health and Human Services, the number of organ transplants doubled from around 15,000 to more than 30,000 annually. However, the number of people awaiting organ donation grew almost sixfold, to nearly 120,000. This is partly due to changes in the donation listing and matching process, but health organizations note it’s also due to some harsh realities, including the fact that while 95 percent of U.S. adults support organ donation, just 48 percent are registered donors.

10. ONLY THREE IN 1000 DEATHS ARE ELIGIBLE FOR ORGAN DONATION.

Properly preserving a donor's organs requires optimal conditions, meaning that only a small percentage of deceased individuals are fit to donate. In most cases, donors experience brain death in a hospital and are stabilized while their organs are harvested. Thanks to medical advancements, more and more patients that experience cardiac death are now fit to donate.

11. MINUTES COUNT WHEN IT COMES TIME TO MAKE THE TRANSPLANT.

A kidney being prepped for transplant. Getty

Because some organs can only be preserved for a few hours outside the body, every minute counts when making the transfer from donor to recipient. Donation organizations coordinate with flight crews, police, ambulances, and other entities to speed along precious organs. The New York Daily News recalled the recent journey a donor heart, which can last just four hours, made from New Hampshire to New York City. It involved a flight, a police escort, and an ambulance racing across the George Washington Bridge.

12. IN 2012, 60 PEOPLE TOOK PART IN A REMARKABLE DONATION CHAIN.

Call it a case of pay-it-forward on steroids. In 2012, a California electrician named Rick Ruzzamenti decided he wanted to donate a kidney to someone in need. The organ went to a man in New Jersey whose own family had wanted to donate but were found incompatible. After the man received Ruzzamenti’s kidney, family members were encouraged to themselves donate a kidney to someone in need, thus beginning a chain that connected donors with organ recipients and family members willing to donate in turn. The chain meandered along for four months, connecting 17 hospitals in 11 states. It ended at the thirtieth donation with a man named Don Terry in Joliet, Illinois.