In American mythology, the (largely White) huddled masses of the Ellis Island era teemed to our shores, tamed the prairies, powered the Industrial Revolution and became the heroes of the American success story. Today’s (largely non-White) immigrants are portrayed somewhat less charitably, often as people who came without marketable skills, looking for a handout.

Now, thousands of genealogists, toiling anonymously, have shattered that myth and upended our perception of American immigrants. No spoilers, but the data shows that the current wave of immigrants is succeeding and assimilating at virtually the same rate as immigrants did a century ago.

“The Mexicans today are just as upwardly mobile as the English and Norwegians of the past,” Stanford University economist Ran Abramitzky told us.

With Leah Boustan, now of Princeton University, Abramitzky is helping to change the way we look at American immigrants during a 14-year effort to follow Americans across generations by linking together their records in one of humanity’s greatest data troves: old decennial census files.

Seventy-two years after each census, the government releases every sheet of data collected by enumerators in a single, magnificent data dump. But for decades, that was more or less the end of it. Piles of magnificent data dumps sat slowly decaying in government warehouses and data centers.

It took pioneering researchers such as Northwestern University’s Joseph Ferrie…