library(tigris)
library(ggplot2)
library(ggthemes)
library(rgeos)
library(sp)
coast <- coastline()
# ggplot really doesn't like a ton of detailed lines so
# we use rgeos::gSimplify to get the structure to a reasonable size
# but we also lose the SpatialLinesDataFrame, so re-bind the
# data from the original spatial structure so we can use fortify
coast_simp <- gSimplify(coast, tol=1/200, topologyPreserve=TRUE)
coast_simp <- SpatialLinesDataFrame(coast_simp, coast@data)
coast_map <- fortify(coast_simp)
gg <- ggplot()
gg <- gg + geom_map(data=coast_map, map=coast_map,
aes(x=long, y=lat, map_id=id),
color="black", fill="white", size=0.25)
gg <- gg + coord_map(xlim=c(-125.0011, -66.9326),
ylim=c(24.9493, 49.5904))
gg <- gg + theme_map()
ggRun the code above in your browser using DataLab