Chronical Events related to SegWit and Bitcon Chash in 2017

25 February 2017
Shaolinfry (anonymous developer) proposes a user-activated soft fork (UASF) on the bitcoin-devs mailing list.

12 March 2017
Shaolinfry proposes his UASF as BIP148 on the bitcoin-devs mailing list.

21 April 2017
Litecoin roundtable agreement ensures Segwit on LTC. This is a result of UASF pressure as miners weren’t signaling for Segwit before.

22 May 2017
Rumors of the New York Agreement: James Hilliard proposes BIP91 for making the 80% threshold for Segwit Activation work.

23 May 2017
The New York Agreement is published.

18 July 2017
A BIP91 Segwit2x client is released.

21 July 2017
BIP91 locks in.

22 July 2017
Bitcoin Cash is announced.

1 August 2017
Bitcoin Cash hard forks off the Bitcoin network.

9 August 2017
Segregated Witness locks in on Bitcoin.

24 August 2017
Segregated Witness is activated.