Geographical projections of a mainland USA map 

library(sf)

Linking to GEOS 3.9.0, GDAL 3.2.2, PROJ 7.2.1

load("US_flat.RData")
US_flat

Simple feature collection with 49 features and 1 field
geometry type:  MULTIPOLYGON
dimension:      XY
bbox:           xmin: -124.6813 ymin: 25.12993 xmax: -67.00742 ymax: 49.38323
geographic CRS: WGS 84
First 10 features:
                         geometry                State
1  MULTIPOLYGON (((-87.46201 3...              Alabama
2  MULTIPOLYGON (((-114.6374 3...              Arizona
3  MULTIPOLYGON (((-94.05103 3...             Arkansas
4  MULTIPOLYGON (((-120.006 42...           California
5  MULTIPOLYGON (((-102.0552 4...             Colorado
6  MULTIPOLYGON (((-73.49902 4...          Connecticut
7  MULTIPOLYGON (((-75.80231 3...             Delaware
8  MULTIPOLYGON (((-77.13731 3... District of Columbia
9  MULTIPOLYGON (((-85.01548 3...              Florida
10 MULTIPOLYGON (((-80.89018 3...              Georgia

plot(st_geometry(US_flat),
     graticule=TRUE,axes=TRUE)
/book/data-management-r/08-spatial-geographical-data/cartographic-projections/5a51b622b5dc043395621cb297a3973b50b34ace1ce3ed13533577023ad64d0e.png 
bbox_US <- st_bbox(US_flat)

c(xcenter = mean(bbox_US[c("xmin","xmax")]),
  ycenter = mean(bbox_US[c("ymin","ymax")]))

  xcenter   ycenter 
-95.84438  37.25658 

laea <- st_crs("+proj=laea +lon_0=-95.8 +lat_0=37.3")
US_proj <- st_transform(US_flat,laea)
plot(st_geometry(US_proj),
     graticule=TRUE,axes=TRUE)
/book/data-management-r/08-spatial-geographical-data/cartographic-projections/cee0c8824fc882d1cf7360fd44245d92e05e933111ba0d6edfda80658f66e944.png