This is the most comprehensive all-time Bitcoin price history chart you will find online, with price data starting in 2009. Updated daily. The chart is interactive:

On 2009-10-05 the market price of Bitcoin is first established at $0.000764/BTC by New Liberty Standard, the first Bitcoin exchange ($1.00 buys 1309.03 BTC.) The exchange rate history is available at two archived pages: first, second. Their last known exchange rate is $0.005472/BTC on 2010-03-02.

On 2010-04-25 the market price is established again at $0.003/BTC, using the daily volume-weighted trading price of the second Bitcoin exchange, BitcoinMarket.com (PayPal USD trades). The owner, dwdollar, actually started operating it on 2010-03-17, however trading data for the first few weeks is—to my knowledge—not available.

After 2010-07-18 the exchange rate is from the CoinDesk BPI v1 API (https://api.coindesk.com/v1/bpi/historical/close.json?start=2010-07-18&end=2022-05-17).

After 2022-05-18 the BPI v1 API has gaps, so the exchange rate is from the CoinDesk Bitcoin XBX index (currently https://production.api.coindesk.com/v2/tb/price/values/BTC?interval=1d&...). For a while I was pulling data from the "BPI v3 API" (https://www.coindesk.com/pf/api/v3/content/fetch/chart-api?query=...) but it was disabled on 2024-11-24 so I switched to the Bitcoin XBX index URL.

After 2025-02-07 there is no clear API where Coindesk publishes the XBX index, so I switched to the cryptocompare BTC price in USD, using the open price of each day (https://min-api.cryptocompare.com/data/v2/histoday?fsym=BTC&tsym=USD&limit=...).