Sue,
Although of manx paternal descent my maternal side where Irish (Cork) immigrants following the mid 1840s crop failures.
In 1847 about 300,000 poor Irish landed in the port.
Born in Liverpool in the 1930s, from memory, I believe I was taught that although some of the notorious "Courts" were still in existence in the Scotland Road area, and some of my people lived in them, the initial clearances started in the 1860s.
This followed the apointment of Dr Duncan, the first Medical Officer of Health in the country.
He was apointed by the Liverpool Corporation following reccomendations by such people as Sir John Simon.
In his first year of office 21,000 people died because of conditions in the city
For example in 1861 in Liverpool there were 12,900 infant deaths, 6,500 were children under five.
Mass burials were regular occurences.
Pioneering work on replacement tenement blocks followed
In 1864 engineers reported still over 3,000 congested courts
By 1871 the work of Duncan was having some effect.
Peter.