diff --git a/NEWS.md b/NEWS.md
index 46417a2..10cba97 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -8,6 +8,7 @@ Several small fixes.
 - Manually add a "states-packge" alias for the package doc since **roxygen2** does not do this by default anymore. 
 - Switch from the deprecated `ggplot2::aes_string()` to `ggplot2::aes()` + the `.data` pronoun in `plot_missing()`. 
 - Fix a **dplyr** join warning in `state_panel()` due to the new "relationship" argument.
+- Update old URLs in README and other documentation.
 
 
 # states 0.3.1
diff --git a/R/data-docs.R b/R/data-docs.R
index da51097..23ca4eb 100644
--- a/R/data-docs.R
+++ b/R/data-docs.R
@@ -88,7 +88,7 @@
 #'
 #' @source
 #' Marshall, Monty G., Ted Robert Gurr, and Keith Jaggers. 2017. ``Polity IV
-#'   Project: Dataset Users' Manual.'' [http://www.systemicpeace.org/inscr/p4manualv2016.pdf]( http://www.systemicpeace.org/inscr/p4manualv2016.pdf)
+#'   Project: Dataset Users' Manual.'' [https://www.systemicpeace.org/inscr/p4manualv2016.pdf](https://www.systemicpeace.org/inscr/p4manualv2016.pdf)
 #'
 #' @examples
 #' data("polity")
diff --git a/README.Rmd b/README.Rmd
index 2dc9dd5..e4ec716 100644
--- a/README.Rmd
+++ b/README.Rmd
@@ -18,7 +18,7 @@ knitr::opts_chunk$set(
 <!-- badges: start -->
 [![R build status](https://github.com/andybega/states/workflows/R-CMD-check/badge.svg)](https://github.com/andybega/states/actions)
 [![CRAN versions](http://www.r-pkg.org/badges/version/states)](https://cran.r-project.org/package=states)
-[![Coverage status](https://codecov.io/gh/andybega/states/branch/master/graph/badge.svg)](https://codecov.io/github/andybega/states?branch=master)
+[![Coverage status](https://codecov.io/gh/andybega/states/branch/master/graph/badge.svg)](https://app.codecov.io/github/andybega/states?branch=master)
 <!-- badges: end -->
 
 Create country-year/month/day panels consistent with the COW or Gleditsch & Ward lists of independent states. I mainly use this for merging different data sources: 
@@ -51,7 +51,7 @@ countries <- state_panel(1991, 2001)
 str(countries)
 ```
 
-- Visualize missing/non-independent cases in your data. See this related [blog post for more details](https://www.andybeger.com/2016/09/14/data-management-and-missing-data/).
+- Visualize missing/non-independent cases in your data. See this related [blog post for more details](https://www.andybeger.com/blog/2016-09-13-data-management/).
 
 ```{r, fig.height = 5}
 data("polity")
@@ -87,10 +87,10 @@ remotes::install_github("andybega/states")
 
 ## Citations
 
-For the [Gleditsch and Ward (G&W) state data](http://privatewww.essex.ac.uk/~ksg/statelist.html):
+For the [Gleditsch and Ward (G&W) state data](http://ksgleditsch.com/statelist.html):
 
 Gleditsch, Kristian S. & Michael D. Ward. 1999. "Interstate System Membership: A Revised List of the Independent States since 1816." International Interactions 25: 393-413.
 
-For the [Correlates of War (COW) state data](https://correlatesofwar.org/data-sets/state-system-membership):
+For the [Correlates of War (COW) state data](https://correlatesofwar.org/data-sets/state-system-membership/):
 
 Correlates of War Project. 2017. "State System Membership List, v2016." Online, https://correlatesofwar.org
diff --git a/README.md b/README.md
index 6f4d0ab..bac1521 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ status](https://github.com/andybega/states/workflows/R-CMD-check/badge.svg)](htt
 [![CRAN
 versions](http://www.r-pkg.org/badges/version/states)](https://cran.r-project.org/package=states)
 [![Coverage
-status](https://codecov.io/gh/andybega/states/branch/master/graph/badge.svg)](https://codecov.io/github/andybega/states?branch=master)
+status](https://codecov.io/gh/andybega/states/branch/master/graph/badge.svg)](https://app.codecov.io/github/andybega/states?branch=master)
 <!-- badges: end -->
 
 Create country-year/month/day panels consistent with the COW or
@@ -70,7 +70,7 @@ str(countries)
 
 - Visualize missing/non-independent cases in your data. See this related
   [blog post for more
-  details](https://www.andybeger.com/2016/09/14/data-management-and-missing-data/).
+  details](https://www.andybeger.com/blog/2016-09-13-data-management/).
 
 ``` r
 data("polity")
@@ -120,14 +120,14 @@ remotes::install_github("andybega/states")
 ## Citations
 
 For the [Gleditsch and Ward (G&W) state
-data](http://privatewww.essex.ac.uk/~ksg/statelist.html):
+data](http://ksgleditsch.com/statelist.html):
 
 Gleditsch, Kristian S. & Michael D. Ward. 1999. “Interstate System
 Membership: A Revised List of the Independent States since 1816.”
 International Interactions 25: 393-413.
 
 For the [Correlates of War (COW) state
-data](https://correlatesofwar.org/data-sets/state-system-membership):
+data](https://correlatesofwar.org/data-sets/state-system-membership/):
 
 Correlates of War Project. 2017. “State System Membership List, v2016.”
 Online, <https://correlatesofwar.org>
diff --git a/man/polity.Rd b/man/polity.Rd
index 177b6c3..1b1cde8 100644
--- a/man/polity.Rd
+++ b/man/polity.Rd
@@ -14,7 +14,7 @@ Data frame
 }
 \source{
 Marshall, Monty G., Ted Robert Gurr, and Keith Jaggers. 2017. ``Polity IV
-Project: Dataset Users' Manual.'' \url{http://www.systemicpeace.org/inscr/p4manualv2016.pdf}
+Project: Dataset Users' Manual.'' \url{https://www.systemicpeace.org/inscr/p4manualv2016.pdf}
 }
 \usage{
 polity