A brief visual history of MARC cataloging at the Library of Congress.

The Library of Congress has released MARC records that I'll be doing more with over the next several months to understand the books and their classifications. As a first stab, though, I wanted to simply look at the history of how the Library digitized card catalogs to begin with.

A couple notes for the technically inclined:
1. the years are pulled from field 260c (or if that doesn't exist or is unparseable, from field 008). Years in non-western calendars are often not converted correctly.
2. There are obviously books from before 1770, but they aren't included.
3. By "books", I mean items in the LC's recently-released retrospective (to 2014) "Books all" MARC files. http://www.loc.gov/cds/products/product.php?productID=5. Not the serial, map, etc. files: the total number is just over 10 million items.

See after the break for the R code to create the chart and the initial version Jacob is talking about in the comments.

my_annotate = function(lab,label,width=40,col="#EEEEEE",...)  {
  annotate(geom="text",...,label=str_wrap(label,width = width),family="OpenSans-CondensedLight", lineheight=0.75,size=3.5,col=col)
}

plot = data %>% filter(marc_record_created_year < 2017, marc_record_created_year>1965, record_date > 1700, record_date < 2017) %>%
  ggplot() + 
  geom_raster() + 
  aes(x=record_date,y=marc_record_created_year, fill=TextCount) + 
  scale_y_continuous(position=c("right"),expand=c(0,0)) + 
  scale_x_continuous(position=c("bottom"),breaks=seq(1770,2020,by=10),limits=c(1770,2025),expand = c(0,0)) + 

           scale_fill_gradientn("Number\nof books\ncataloged", trans="log10",
                       colors = rev(magma(5)),breaks=outer(c(1,2,5,10),c(1,10,100,1000,10000),"*") %>% as.vector %>% unique) + 
  theme_bw() + 
  theme(legend.key.height = unit(1,"in"),
        plot.title = element_text(size=22)
  ) + 
  annotate("segment",y=1968,yend=2014,x=1968,xend=2014,lwd=1.5,color="white",lty=2) + 
  labs(x="Year of book",y="Year of MARC record",title="MARC cataloging at the Library of Congress",
       subtitle="A brief visual history comparing the year that records were created (left to right) with the year that the books described in them were published" %>% str_wrap) +
  coord_flip() + 
  my_annotate(y=2013,x=2017,label="Books along the dashed line were cataloged in the same year as they were published; this has always been the most common practice",hjust=1,vjust=0,col="black") + 
  my_annotate(y=1995,x=1999,label="Anything to the upper left of this line was (supposedly) cataloged before it was published: this is impossible! These are all errors of some type.",hjust=1,vjust=0,col="black") + 
  my_annotate(y=1975,x=1969,label="MARC cataloging began in 1968; in the first years, only new books were added.",hjust=0,vjust=0.5,width=40,col="#EEEEEE") + 
  annotate(geom="segment",x=1967,xend=1969,y=1967,yend=1975,col="grey") + 
  my_annotate(y=1975,x=1960,label="In the early 1970s catalogers began to input older books: by 1972, there were hundreds of books a year entered from the early twentieth century",hjust=0,vjust=0.8,width=35,col="#EEEEEE") + 
    annotate(geom="segment",x=1910,xend=1960,y=1971,yend=1974.5,col="#DDDDDD") + 
    annotate(geom="segment",x=1950,xend=1960,y=1970,yend=1974.5,col="#DDDDDD") + 
    annotate(geom="segment",x=1960,xend=1960,y=1969,yend=1974.5,col="#DDDDDD") + 
  my_annotate(y=2000,x=1940,label="It took until 2000 for the backlog to be (mostly) cleared: the lighter patches here show that only a few records from the mid-twentieth century were being digitized",hjust=1,vjust=0.8,width=30,col="#EEEEEE") + 
    annotate(geom="segment",x=1940,xend=1955,yend=2003,y=2000.5,col="#DDDDDD") + 
    annotate(geom="segment",x=1940,xend=1920,yend=2003,y=2000.5,col="#DDDDDD") +
    my_annotate(y=1995,x=1902,label="There is a dark band in the year 1900, which is used as a catchall year for books published anytime in the century",hjust=1,vjust=0,width=30) + 
  annotate("rect",ymin=1968, ymax=2014, xmin=1899,xmax=1902,fill=NA,color="#DDDDDD",alpha=.5) + 
  annotate("rect",ymin=1994.8, ymax=1997.2, xmin=1850,xmax=1896,fill=NA,color="#DDDDDD",alpha=.5) + 
  my_annotate(y=1993.5,x=1880,label="A horizontal line shows that 1996 was an especially furious year of digitizing older records from the 19th and 20th centuries",hjust=1,vjust=0.5,width=30) +
      my_annotate(y=2002,x=1830,label="Staircase patterns moving up and to the right show smaller efforts that proceeded in chronological order through a subcollection. It took about 6 years to catalog 25 years worth of books from 1825 to 1850",hjust=1,vjust=0,width=35,col="#111111") + 
    annotate(geom="segment",x=1838,xend=1830,yend=2002,y=2007) +
      annotate(geom="segment",x=1800,xend=1830,yend=2002,y=1999) +

  annotate("rect",ymin=2007,ymax=2014,xmin=1848,xmax=1825,fill=NA,color="black",alpha=.5) +
  annotate("rect",ymin=1997,ymax=2001,xmin=1780,xmax=1800,fill=NA,color="black",alpha=.5)


ggsave(plot,device="png",filename="~/Pictures/MARC.png",width=7.5,height=20)