How do you address the failures of laissez-faire capitalism?

Laissez-faire capitalism was a popular ideology in 19th-century and 18th-century France. In France, due to a poor harvest, the government was forced to intervene to prevent a famine. This once again happened during the Irish Famine; the Whigs, who supported laissez-faire, stopped all foreign aid to Ireland and let the Irish starve, thinking the problem would solve itself.

Then there are the terrible wages, working and living conditions.

https://www.bbc.co.uk/bitesize/guides/zkxrxyc/revision/2

www.britannica.com/money/laissez-faire

https://www.investopedia.com/terms/l/laissezfaire.asp

https://en.wikipedia.org/wiki/Laissez-faire

https://www.britannica.com/event/Great-Famine-Irish-history

And no, the US has never had laissez-faire. The US has always been influenced by Mercantilism.

https://en.wikipedia.org/wiki/American_School_(economics))