The attorney who was to offer the information, Natalia Veselnitskaya, was described in one email as a "Russian Government attorney who is flying over from Moscow."
After months of allegations, the emails showed the first concrete evidence of contacts between members of the Trump inner circle and Russia, including the offer of help for Mr. Trump in his campaign against Clinton.
The release of the emails showed off the shifting explanations from Trump Jr. about the meeting and the reasons behind it. When the first stories from the New York Times surfaced over the weekend, the President's oldest son said it was a meeting called to discuss adoption policies dealing with Russian children.
These emails include no mention of that subject - and the email chain is titled, "FW: Russia - Clinton - private and confidential."
The email exchanges with publicist Rob Goldstone emphasized what was being offered: "This is obviously very high level and sensitive information but is part of Russia and its government's support for Mr Trump."
Democrats in Congress immediately seized on the details of the emails.
"This sure looks like an effort to communicate, cooperate, and collude with the Russian government," said Sen. Jeff Merkley (D-OR).
"Collusion plain and simple," said Rep. Norma Torres (D-CA).
"It's now in black and white," said Rep. Sheila Jackson Lee (D-TX).
"If this isn't treasonous, I'm not sure what is," said Rep. Seth Moulton (D-MA).
For the most part, Republicans in Congress stuck behind the President, saying this latest email release amounted to nothing, echoing talk in recent days that it was a "nothingburger."
But for one Republican, Rep. Lee Zeldin (R-NY) - who had belittled the Trump Jr. story on Monday from the New York Times - it was something different.