It's Valentine’s Day, a blockbuster holiday for the greeting card business. As it turns out, the very first American-made love cards were made in Worcester by a woman known as the "mother of the American valentine."

Her name was Esther Howland and the American Antiquarian Society in Worcester holds a large collection of her valentines.

Curator of Graphic Arts Lauren Hewes gingerly handles one of Howland's valentines that's about 5 by 3 inches in size. It's lacy with a colorful print of a young, love-struck couple strolling along a garden path. Inside there's a mushy bit of verse, printed in red. Hewes reads it for me.

Oh, could I hear thee once declare

That fond affection lives for me,

Oh, could I once delighted share,

The sweet return of love from thee.

Sure, it's corny, and sweet — but that's not what attracts Hewes to Howland's legacy.

Esther Howland, the "mother of the modern valentine" (Courtesy of AAS)

"She's a businesswoman," Hewes said. "I mean it is lacy, beautiful, feminine material that she's producing, but she's producing it successfully and making money."

Howland started making and selling Valentine's Day cards when she was just 20 years old.

After graduating from Mount Holyoke College, she had a profitable hunch in 1848. Before then, Americans hoping to woo their lovers either made their own valentines or bought elaborate cards imported from overseas.

Howland received a fancy, British card and brought it to her father, who owned the largest stationary company in Worcester. Hewes said her "pitch" went something like, "This is great, these are beautiful, why don't we sell these?"

He was intrigued by his daughter's idea.

"So she made up some little sample valentines with some scraps and things she had gotten from her father," Hewes continued, "and she sent them out with her brother that February." As the story goes, Howland's expectations were low. She expected maybe 200 orders.

She was way off.

"She got 5,000 orders," Hewes said with a smile.

To fill them Howland hired a small army of women who cranked out valentines in an assembly line on the third floor of her Worcester home. Two years later Howland incorporated and the New England Valentine Co. was born. Hewes said the young entrepreneur's timing was right on.

"And I think [she] caught the wave of sentimentality in America just right, because this is the period when romantic love is something to be celebrated, and not, like the Puritans might say, tucked under the rug," Hewes said.

But the sign of a truly astute businessperson is always the bottom line. So, how much was she making?

Numerous Worcester streets signs pay homage to Esther Howland's legacy as the "Mother of the Valentine." (Andrea Shea/WBUR)

"It goes from $25,000 to $75,000 in the various press reports," Hewes replied.

Not too shabby — especially for the mid-1800s, and especially for a woman.

Today collectors seek out Howland Valentines. If they're in pristine condition they can be worth as much as $300 to $400, according to Elizabeth Baird, a dealer of ephemera — or antique papers, books, art and valentines — based in Maine.

"No one ever threw a Valentine away. I mean, they just had to save them," Baird reflected. "Quite often they’re wrapped with a ribbon and they’re in a candy box up in the attic, in the bottom of a trunk, something like that."

So keep your eyes peeled. Howland valentines are prized, Baird said, because Howland was the first. A slew of copycats followed her lead, and the industry boomed.

Howland ran her company for about 40 years before selling it in 1888 to her main competitor in Worcester — George C. Whitney.

And while she entertained many business suitors leading up to that sale, Esther Howland herself never married.