Their sons were killed in Iraq about a week apart.
So when Karen Meredith heard the grieving parents of a decorated Muslim Army officer being belittled by Donald Trump, she cried.
Meredith said she hadn't wept over her son's death for a long time, but the Republican presidential nominee "ripped the wounds right open again."
"You don't attack one Gold Star family, because if you do, you're attacking a lot of us," Meredith, 62, of Mountain View, California, said Monday.
Trump has been engaged in an emotionally charged feud with Khizr and Ghazala Khan, whose son, Capt. Humayun Khan, was killed in Iraq by a suicide bomber on June 8, 2004. Trump stoked outrage by implying that Ghazala Khan did not speak while standing alongside her husband at last week's Democratic convention because of their Muslim faith. And he disputed their right to question his grasp of the Constitution.
Some of America's Gold Star families, or those who lost loved ones in war, have demanded that Trump apologize.
Meredith organized a letter to Trump that has been signed by 23 families so far. She said she did so after seeing so much "hurt and anger" among Gold Star families on social media.
Trump refused to back down Monday, complaining anew that he has been "viciously attacked" by the Khans.
Meredith's son and only child, Army 1st Lt. Kenneth Michael Ballard, was killed during a firefight in Iraq on May 30, 2004, at age 26.
"Most people in this country, before this, did not know what a Gold Star family was, let alone what our sacrifice was," Meredith said. "For him to attack a Gold Star family and not understand the grief that Mrs. Khan was going through and why she wouldn't have spoken, just validated my feelings toward Mr. Trump as an unfeeling, empty person."
The letter was released publicly on Monday by VoteVets.org, a left-leaning group dedicated to electing liberal veterans to Congress. Meredith is a Democrat but said this is a nonpartisan issue.
Celeste Zappala, who also signed the letter, said the grief that Gold Star families suffer earns them the right to say whatever they want. Zappala's son, Army Sgt. Sherwood R. Baker, was also killed in Iraq in 2004. She said she cried after hearing Trump's comments, too.
"Mr. Trump has made a firestorm happen that didn't need to happen and that insults everybody who served," said Zappala, of Philadelphia. "Nobody should say anything other than 'Thank you for your service.'"
Both Zappala and Meredith stressed that they aren't speaking on behalf of all Gold Star families, and that there are others who back Trump.
Ryan Manion Borek, a Republican from Doylestown, Pennsylvania, said she is happy the Khans got to share their son's story and hopes the backlash prompts both candidates to address Gold Star issues. Her brother, Marine 1st Lt. Travis Manion, was killed in Iraq in 2007.
Gold Star families represent such a small fraction of the population, "it's super important that the people making the decision to send men and women off to war understand what that means," said Borek, who hasn't decided which candidate she will vote for.
Prominent Republicans spoke out Monday against Trump. Arizona Sen. John McCain, a prisoner of war in Vietnam, said that while the party has bestowed upon Trump the nomination, "it is not accompanied by unfettered license to defame those who are the best among us."
The Veterans of Foreign Wars said it won't tolerate anyone berating a Gold Star family member for exercising his or her right to free speech.
President Barack Obama addressed the Disabled American Veterans' annual conference in Atlanta on Monday. He didn't mention Trump by name but implicitly rebuked him for criticizing the Khan family.
"No one — no one has given more for our freedom and our security than our Gold Star families," Obama said. "They continue to inspire us every day, every moment."
Ami Neiberger-Miller, of Purcellville, Virginia, knows the Khans because her brother is buried near their son at Arlington National Cemetery. Army Spc. Christopher Neiberger was killed in Iraq in 2007.
She said she emailed the Khans after the Democratic National Convention speech, telling them how brave they were. As for Trump's response, Neiberger-Miller said she found it "very disturbing and distasteful."
"The comments about Mrs. Khan because she didn't speak on stage, that seemed very cruel," she said. "I actually saw her standing there as a kind of strength. As a bereaved parent, that might be what she could do that day."
Neiberger-Miller said the one positive thing to come out of this may be that Americans are learning more about Gold Star families.
"We're the families who really live with the price of war, who live with the price of service and honor and duty to country, and all of the things that go with it," she said. "There is a sense of disconnect at times between us and the rest of the country."
Associated Press radio correspondent Julie Walker in New York and White House reporter Josh Lederman contributed to this report. McDermott reported from Providence, Rhode Island. Adcox reported from Columbia, South Carolina.