In the 1970s, editor and firebrand Clement Costello, who was known for walking around in a cape, wrote that the U.S. should annex Mexico and was credited with helping to ruin John Kerry's chances of winning the 5th Congressional District seat in 1972.

The Sun was once known beyond its circulation area as the home base of the late columnist Paul Sullivan, who until 2007 hosted a nighttime talk show on WBZ radio in Boston.

One of the paper's most famous alumnus is Jack Kerouac, a Lowell native who worked as a sports reporter for The Sun before going on to greater fame as poet laureate to the Beat Generation.

Another Sun alumnus is Tom Squitieri, who won the Overseas Press Club Madeleine Dane Ross Award for his reporting on divided Cambodian refugee families living in Lowell and Thailand.

In its earliest years, The Sun provided the growing Irish Catholic population a voice in a mill city that was run by wealthy Protestant factory owners.