Almost certainly a head-smakingly simple solution …

Can someone help me figure out why when I add the legend to my histogram plot the bars are split in colour horizontally (and not just the bars being split), and why are the bars not lining up with the x-axis numbers? The bars should not be centered on top of a number, rather, the edge of the bar should line up with the tick marks.

I am trying to generate cumulative relative frequency histogram with polygon in R base that look like this:

I am trying to generate cumulative relative frequency with polygon in R base that look like this: