title: How to add a legend on a multiple line graph in R?
body: <p>I am trying to plot two different datasets on the same plot. I am using this code to add the lines and to actually plot everything</p>
  
  <pre><code>ggplot()+
  geom_point(data=Acc, aes(x=Year, y=Accumulo), color="lightskyblue")+
  geom_line(data=Acc, aes(x=Year, y=RM3), color="gold1")+
  geom_line(data=Acc, aes(x=Year, y=RM5), color="springgreen3")+
  geom_line(data=Acc, aes(x=Year, y=RM50), color="blue")+
  geom_line(data=Vulcani, aes(x=Year, y=Accumulo.V), color="red")+
  theme_bw()+
  scale_x_continuous(expand=expand_scale(0)) + scale_y_continuous(limits=c(50,350),expand=expand_scale(0))
  </code></pre>
  
  <p>but I can't find any way to add a legend and add custom labels to the different series. I find a way to add legends on a single dataset, but I can't find a way to add to this one a legend on the side</p>