History of Bitcoin block sizes: what was the limit before the current 1 MB?

According to https://en.bitcoin.it/wiki/Block_size_limit_controversy , BTC initially had a limit of "500-750 kb" before Satoshi increased it to 1 MB in 2010. Does anyone have more accurate information on the topic? I'm trying to create a Bitcoin timeline showing the different events that led to the current BTC state, including when Bitcoin XT was DDOSed and failed, when Gavin was kicked, Blockstream, Tether, everything.