It’s early Sunday morning, and I’m on my way into Washington, D.C. to get caught up on some paperwork at the office. As I cross the Anacostia River on the New York Avenue Bridge, a large raptor catches my eye. Its strong wings carry it down the river, with the National Arboretum on its right and the Kenilworth Aquatic Gardens on the left. The bird’s white head and tail are in sharp contrast to the dark brown feathers that cover the rest of its body. A bald eagle (Haliaeetus leucocephalus) is flying over the capital of the United States.

While it’s still rare to see a bald eagle over the Anacostia, it’s becoming more common. Just south of the city, bald eagles frequent the skies along the Potomac River. Their increasing numbers here are part of an exceptional national comeback that dates to the early 1970s.

Bald eagles are big birds. Males can weigh up to 10 pounds, carried by wings that stretch to 6.5 feet.

In an oddity of the avian world, eagles and other species of the family accipitridae exhibit “reversed sexual size dimorphism,” a phrase which means that the girls are bigger than the boys. Female bald eagles can reach 14 pounds with wingspans of up to 8 feet.

I can’t tell the sex of the bird I’m watching without its mate nearby for comparison. But I can tell that it’s at least 4 years old. Bald eagles take that long to adopt their iconic snow-white head, neck and tail. The adult bird I’m watching also has a bright golden beak. In younger birds, the beak is dark.

In 1782, the United States adopted the bald eagle as our national symbol, and it was an good choice for the young nation. The powerful, regal-looking raptor is the only eagle unique to North America. Estimates of bald eagles in the lower 48 states around 1800 vary widely, but there were probably more than 50,000 pairs.

Loss of habitat, hunting, and especially the wide-spread use of pesticides like DDT combined to bring the population to the brink of extinction by 1963. Just 417 pairs were counted in the lower 48 states that year. The number of bald eagles in the Chesapeake watershed had dropped to about 80 pairs.

The eagle that I am watching fly effortlessly down the Anacostia is one of 9,700 pairs in the United States today, a number that does not include the robust population in Alaska. There are twice as many breeding pairs in the Chesapeake now as existed in the entire lower 48 states when the bird was declared endangered 40 years ago.

These birds, which mate for life, don’t reach sexual maturity until they are about 4 or 5 years old, and usually raise just one or two chicks annually. The restoration process is a long one.

Their extraordinary recovery from near extinction has been the result of the work of many people, but none more so than Rachel Carson. In a wonderful coincidence of timing, the nation celebrated the centennial of Carson’s birth at the end of May this year. By the end of June, the U.S. Fish and Wildlife Service is expected to finalize its decision to remove the bald eagle from the list of threatened and endangered species.

Carson trained as an aquatic biologist, earning her master’s degree from Johns Hopkins University. She worked for the predecessor of the U.S. Fish and Wildlife Service, combining her scientific training with an extraordinary gift as a writer.

She wrote radio scripts for the government, Sunday feature articles for The (Baltimore) Sun, and essays for magazines. Eventually she rose to become editor-in-chief of all Fish and Wildlife publications.

Carson won the National Book Award in 1953 for “Under the Sea Wind.” A second popular and critically acclaimed book followed, staying on the New York Times Best Seller List for 86 weeks.

In spite of her fame, though, few people were ready for “Silent Spring” when it was published in 1962. The book combined careful scientific research with compelling prose. She explained that bald eagles, at the top of the food chain, were accumulating fatal levels of pesticides in their bodies. These chemicals were reducing the thickness of bald eagle egg shells, preventing the birds from successfully incubating their young.

The book was an immediate sensation, sparking outrage among most Americans and attacks from the powerful chemical industry.

A special commission appointed by President Kennedy to investigate Carson’s charges validated her findings. Within five years of the publication of “Silent Spring,” bald eagles were officially declared endangered. DDT was banned for use in the United States soon after. Bald eagle populations across the nation began to increase on a trajectory that hasn’t slowed to this day.

The bald eagle I am watching grace the early morning sky doesn’t know that it owes its life to the work of a Washington, D.C. bureaucrat from the middle of the last century.

As a D.C. bureaucrat myself, I ponder Carson’s work as well as the graceful flight of the eagle, and I smile. Rarely has going to work on a Sunday been so inspiring.