The collapse of bird populations in the USA in the late 1800s thru early 1900s was very much about feathers.
At its peak the feather trade had feathers that were worth more than gold. Commercial hunters would shoot birds out of the sky and sell feathers by the pound, in literal huge crates. Egrets were especially sought after for their beautiful breeding plumage, which was used in fancy hats and accessories. This wrought havoc on the poor birds because they only ever had this plumage during breeding season, so not only were the breeding birds dying, they were leaving next generation's chicks and eggs behind to die of neglect.
Beyond hats, the gentleman's art of fly tying was also a popular art form, more for the sake of showing off one's rare collection of feathers and art than for actual fishing.
There was some meat hunting as well before the banning of commercial hunting, mostly ducks and geese, which also drifted close to extinction as they were taken to be sold in markets.
Even white tailed deer, the ubiquitous animal that's found all over north America in truly ridiculous numbers, came dangerously low. But meat wasn't where the money was when it came to birds. It was feathers.
The Lacey act banned commercial hunting in the United States, putting an end to the constant unregulated commercial killing to fill market stalls with meat (which incidentally is why you don't see venison in most supermarkets in the states. Only farmed deer is legally allowed to be sold.)
And the Migratory Bird Treaty Act made it a crime to not only kill a bird, but to even posess a single feather from one. Most people won't buy a hat that would get them arrested if they wore it outside, so the market for feathers was gutted.
Even though feather hats aren't popular in this day and age, nobody is in a hurry to amend these laws, as birds in general are well loved and popular animals and still very much threatened by other stressors such as pollution and habitat loss.
