Anytime you write a letter, you use the ZIP code. What is that code, and when did people start using it? More importantly for the postal service, how do you get an entire country's population to memorize and add a seemingly random string of numbers to their addresses?

The answer, in the 1960s, was Mr. Zip, a jaunty cartoon postman, designed to make the new ZIP code cause memorable and approachable.

This website discusses the ways in which Mr. Zip was deployed as an educational and advertising device. The majority of the content consists of an essay divided into smaller, more manageable subpages. However, sprinkled throughout, you'll find Mr. Zip comics; merchandise, such as board games and lunchboxes; promotional materials; PSA videos; a memo; photographs; and postage stamps.

This video describes what each number of the ZIP code represents, which could be a hook if you decide to introduce Mr. ZIP in the classroom. Ultimately, the content is not likely to be of direct use in the classroom but may be of more interest as trivia or to flesh out background knowledge for related lessons.

This collection presents 1,395 photographs by the American photographer, music and dance critic, and novelist Carl Van Vechten (1880-1964). The site consists primarily of studio portraits of celebrities, most of whom were involved in the arts, including actors, such as Marlon Brando and Paul Robeson; artists, such as Marc Chagall and Frida Kahlo; novelists, such as Theodore Dreiser and Willa Cather; singers, such as Ethel Waters and Billie Holiday; publishers, such as Alfred A. Knopf and Bennett Cerf; cultural critics, such as H. L. Mencken and Gilbert Seldes; and figures from the Harlem Renaissance, such as Langston Hughes, Countee Cullen, and Zora Neale Hurston.

More than 80 photographs capture Massachusetts and Maine landscapes and seascapes; others include eastern locations and New Mexico. Many photographs of actors present them in character roles. Searchable by keyword and arranged into subject and occupational indexes, this collection also includes a nine-title bibliography and background essay of 800 words on Van Vechten's life and work. A valuable collection for the documentation of the mid-20th-century art scene.

Featuring texts by and about Martin Luther King Jr., this regularly updated website currently contains more than 1,400 speeches, sermons, and other writings, mostly taken from five volumes covering the period from 1929 to 1968. (These are listed in the Published Documents section under Papers.)

In addition, sixteen chapters of materials published in 1998 as The Autobiography of Martin Luther King Jr. are available. The website presents important sermons and speeches from later periods, including "Letter from a Birmingham Jail," the March on Washington address, the Nobel Peace Prize acceptance speech, and “Beyond Vietnam.” Additional materials include an interactive chronology of King's life, two biographical essay, over twenty audio files of recorded speeches and sermons, and twelve articles on King. More than thirty photographs complete the website.

The King Papers Project is valuable for studying King's views and discourse on civil rights, race relations, nonviolence, education, peace, and other political, religious, and philosophical topics.

This archive of 1,500 photographs taken by Teenie Harris, photographer for the Pittsburgh Courier, "one of the largest and most influential Black newspapers in the country," documents African American urban life in Pittsburgh from the 1930s to the 1960s. This is a sample of the 80,000 images that make up the full collection. Many of the images have not been identified and the site's authors ask assistance (a submission form accompanies each image).

Visitors can browse the collection through 15 galleries of 100 images each. They can also comment on images and view the comments of others. Following the link to the Teenie Harris image collection in the Historic Pittsburgh Images Collections at the University of Pittsburgh allows visitors to browse the 541 images that have been identified with full captions. The site also offers a chronology of Harris's life. This site is useful for researching the history of Pittsburgh and its African American community as well as urban history or African American history in general.