It was dropping in the north because of the lockdown and social distancing practices.
The outbreak in the south was less than in the north? I presume you mean in April-May? Because the south, has been getting hammered.
The top 5 states are Ca, Texas, Fl, NY, Ga. Texas, Fl and Ga are the highest per capita rate.
Texas, Fl, Ca all have over 200k more cases than NY. Ny has the largest death toll by far, largely because of poor handling on all levels of government, the population density, speed at which it hit, and the lack of knowledge in how to treat the virus.