Red Red Robin

Our most abundant songbird is described by Cornell’s All About Birds:

The quintessential early bird, American Robins are common sights on lawns across North America, where you often see them tugging earthworms out of the ground. Robins are popular birds for their warm orange breast, cheery song, and early appearance at the end of winter. Though they’re familiar town and city birds, American Robins are at home in wilder areas, too, including mountain forests and Alaskan wilderness.

American Robin at Hagerman NWR, by Lee Hatfield

According to Journey North,

Robins were named by homesick European settlers for their beloved and familiar little Robin Red-breast, which has a color pattern brighter but somewhat similar to our robin, though the two species are not closely related. 

Connecticut, Michigan and Wisconsin all have named the robin their state bird.

If Robins are a ”sign of Spring”, why are we seeing them now?  From Cornell's Project Feeder Watch:

As with many birds, the wintering range of American Robins is affected by weather and natural food supply, but as long as food is available, these birds are able to withstand quite severe cold.

American Robins do migrate, but their year-round range covers nearly all of the continental United States. Only the very northern edges of the central and eastern states that border Canada fall north of the American Robin’s winter range.
In winter robins form nomadic flocks, which can range in size from anywhere between 50 birds in the north to thousands in the south. The flocks break up in the day while foraging and then gather up again at night to roost in trees. 

According to the Audubon 's Guide to North American Birds, 

Robins do much foraging on the ground, running and pausing on open lawns; apparently locating earthworms by sight (not, as had been suggested, by hearing them move underground). When  they are not nesting, usually forage in flocks.  Robins forage for worms in warm weather and eat fruit and berries in cold weather

If you want to feed American Robins in your backyard, they prefer fruit, mealworms, hulled sunflower seeds, peanut hearts, and suet in a ground or platform feeder; you will want to provide a water source also.

Most people are familiar with the color "robin’s egg blue”.  The Audubon site describes breeding and nesting:

Robin nest - vintage art

Males choose a territory and pursue a mate.  The female does most of the nest building, then lays 3 – 7 pale blue eggs. Incubation takes about two weeks and fledging slightly more than two week later.  Both parents fed the young.  Robins may have 2- 3 broods per season.

Wikipedia reports that

"The Robin is a figure in poems about spring and in American popular music such as "When the Red, Red Robin (Comes Bob, Bob, Bobbin' Along)", written by Harry M. Woods, and for comic fans, we learned that although the comic-book superhero Robin was inspired by an N. C. Wyeth illustration of Robin Hood, a later version had his mother nicknaming him Robin because he was born on the first day of spring; his red shirt suggests the bird's red breast."

In Native American cultures,

Robins are often portrayed as industrious, "can-do" birds, who are frequently rewarded for their work ethic.

In some tribes, the bright red color of a robin's breast is associated with fire, and robins feature in legends as either guardian or thief of fire.

In other legends, the caring parental behavior of robins is noted, and in some tribes, it is considered good luck for a pregnant woman to see robins feeding their young.

In the Blackfoot tribe, robins are a symbol of peace and the presence of robins was said to be a sign that a camp or village would be safe from attack.

The Hopi see the robin as a directional guardian, associated with the south.  

The well-known nursery rhyme, Little Robin Redbreast,  is said to have no historical significance, but rather, teaches children about  natural enemies, according to Rhymes.org

Little Robin Red Breast

Little Robin Red breast sat upon a tree,
Up went pussy cat and down went he;
Down came pussy, and away Robin ran;
Says little Robin Red breast, "Catch me if you can".
Little Robin Red breast jumped upon a wall,
Pussy cat jumped after him and almost got a fall;
Little Robin chirped and sang, and what did pussy say?
Pussy cat said, "Meeow!" and Robin jumped away.

Vintage greeting incorporating Robin