Present at least one pivotal legal and historical occurrence that resulted in this shift of public health effort.

One pivotal legal and historical occurrence that resulted in a shift of public health effort was the passing of The National Health Insurance Act (NHIA) in 1997. This law expanded access to healthcare by requiring all employers to provide insurance coverage for their employees, while also establishing a system through which all citizens could be insured regardless of income or employment status. Medicaid/Medicare programs were also created as part of this legislation, providing low-income individuals with quality healthcare regardless of their ability to pay.

Additionally, the NHIA provided incentives for medical providers and insurance companies to reduce costs related to treatment and services thereby making them more accessible than before. Other provisions included the establishment of non-profit health care organizations focused on educating people about preventive measures; creating initiatives aimed at improving nutrition among individuals receiving federal assistance; increasing access to family planning services for those who would not have otherwise been able to afford it etc..

All these changes allowed more people across the US access to high quality health care services while providing greater protection against financial danger due an illness or injury. As such, this act helped revolutionize how public health systems operate and serve as one example that demonstrates how laws can play an integral role in impacting overall population health outcomes.