house {openintro}

United States House of Representatives historical make-up

Description

The make-up of the United States House of Representatives every two years since 1789. The last Congress included is the 112th Congress, which completed its term in 2013.

Usage

house

Format

A data frame with 112 observations on the following 12 variables.

congress

The number of that year's Congress

year_start

Starting year

year_end

Ending year

seats

Total number of seats

p1

Name of the first political party

np1

Number of seats held by the first political party

p2

Name of the second political party

np2

Number of seats held by the second political party

other

Other

vac

Vacancy

del

Delegate

res

Resident commissioner

Source

Party Divisions of the House of Representatives, 1789 to Present. https://history.house.gov/Institution/Party-Divisions/Party-Divisions.

Examples

library(dplyr)
library(ggplot2)
library(forcats)

# Examine two-party relationship since 1855
house_since_1855 <- house |>
  filter(year_start >= 1855) |>
  mutate(
    p1_perc = 100 * np1 / seats,
    p2_perc = 100 * np2 / seats,
    era = case_when(
      between(year_start, 1861, 1865) ~ "Civil War",
      between(year_start, 1914, 1918) ~ "World War I",
      between(year_start, 1929, 1939) ~ "Great Depression",
      between(year_start, 1940, 1945) ~ "World War II",
      between(year_start, 1960, 1965) ~ "Vietnam War Start",
      between(year_start, 1965, 1975) ~ "Vietnam War Escalated",
      TRUE ~ NA_character_
    ),
    era = fct_relevel(
      era, "Civil War", "World War I",
      "Great Depression", "World War II",
      "Vietnam War Start", "Vietnam War Escalated"
    )
  )

ggplot(house_since_1855, aes(x = year_start)) +
  geom_rect(aes(
    xmin = year_start, xmax = lead(year_start),
    ymin = -Inf, ymax = Inf, fill = era
  )) +
  geom_line(aes(y = p1_perc, color = "Democrats")) + # Democrats
  geom_line(aes(y = p2_perc, color = "Republicans")) + # Republicans
  scale_fill_brewer(palette = "Pastel1", na.translate = FALSE) +
  scale_color_manual(
    name   = "Party",
    values = c("Democrats" = "blue", "Republicans" = "red"),
    labels = c("Democrats", "Republicans")
  ) +
  theme_minimal() +
  ylim(0, 100) +
  labs(x = "Year", y = "Percentage of seats", fill = "Era")