Tuesday afternoon (Aug. 8), Glen Campbell's family shared the sad news that he had died after a struggle with Alzheimer's disease.

"It is with the heaviest of hearts that we announce the passing of Glen Travis Campbell, at the age of 81" was the Twitter post.

His daughter, Ashley Campbell, quickly posted a poignant photo.

And less than 10 minutes later, the country world started to respond to the news. And they haven't stopped posting their heartfelt messages since.

Tim McGraw was one of the first artists to react to the news online.

So was David Nail, who told me back in 2009 that Campbell's 1969 album Galveston changed his life, and made him want to be a country singer.

Artists from all over the genre -- the rookies and the legends -- had the kindest words for the iconic country singer.