Paul Madison tells us that the term "every one" has taken on a new meaning and directs our attention to nGrams to emphasize his point. He notes:
. . . I forgot to send a link to google nGrams like I said I would at out last meeting. The main website is https://books.google.com/ngrams
Here's an example of how nGrams can be used to find "correct" grammar as it changes over time: When were the words "every one" more correct than "everyone"? The answer may (or may not) surprise you:
There's a bit of an oversight here. The term Madison is referencing is to a group, true, but there's something missing from the explanation. The thing is "every one" can be broken down into "each one of . . ." and relates to pinpointing one object or person individually out of the entire group.
Compare "every one", for example, "each one in the group" to "everyone" or "everybody" which mean "all of the people" or "all who are/were there." It's inclusive and looks at no single instance as an example; it looks at the entire collection. When musing over a term and trying to determine whether an alternative is correct or whether the term has really evolved, test it. Say it in another way while maintaining the gist of the intended meaning. As with this example, is everybody in the room what's intended or is each apple in the basket what's being highlighted.
It's a good idea to stay open to using reference tools. Just be careful that you're researching the right information. Take some time to explore nGrams.