A “sock hop” (or “sox hop”) is where the dancers take off their shoes and dance in their socks. This preserves both shoes and the dance floor. “Sock hop” dances were popular in the 1940s and 1950s, before modern sneakers were invented.
 
“Sock hop” was printed in the Hammond (IN) Times on December 5, 1941. “Sweater and sox hop” was printed in The Sunday Courier And Press (Evansville, IN) on March 7, 1943. “Sox-Hop” was printed in the Evansville (IN) Press on April 26, 1943.
 
     
Wikipedia: Sock hop
A sock hop or sox hop, often also called a record hop or just a hop, was an informal sponsored dance event for teenagers in mid-20th-century North America, featuring popular music.
 
History
Sock hops were held as early as 1944 by the American Junior Red Cross to raise funds during World War II. They then became a fad among American teenagers in 1948. Sock hops were commonly held at high schools and other educational institutions, often in the school gym or cafeteria. The term came about because dancers were required to remove their hard-soled shoes to protect the varnished floor of the gymnasium. The music at a sock hop was usually played from vinyl records, sometimes presented by a disc jockey. Occasionally there were also live bands.
 
In later years, “hops” became strongly associated with the 1950s and early rock and roll. Danny and the Juniors sang “At the Hop” in 1957, which named many popular dances and otherwise documented what happened at a hop. In subsequent decades, with the widespread popularity of sneakers and other types of indoors-only shoes, the practice of removing shoes was dropped.
         
5 December 1941, Hammond (IN) Times, pg. 26, col. 6:
SOCIAL EVENTS ON
PHAMBAS CALENDAR
(...)
Details concerning the “sock hop” to be given Feb. 17 were talked over, also, and it was agreed to announce them at a later date.
   
16 February 1942, Hammond (IN) Times, pg. 6, col. 6:
Phambas Club’s
‘Sock Hop’ Is
Amusing Affair
One of the season’s gayest and amusing dances for the high school crowd was given Saturday evening at the Phambas club at the Lake Hills Country club. Calling their party the “Sock hop,” the girls carried through the “sock” theme by checking all shoes at the door and presenting their guests with blue and silver programs which listed such dances as the “Hosiery run,” the “Service Weight stomp” and the “Ankle hop.”
   
24 February 1943, Hammond (IN) Times, “New President of Phambas,” pg. 12, col. 5:
The highlight of the meeting however, was the completion of plans for the second annual Sock-Hop to be held at the Woman’s club on March 6.
   
7 March 1943, The Sunday Courier And Press (Evansville, IN), “Hold Sweater Hop,” pg. 6-C, col. 4:
Seventy-five Y. W. C. A. Girl Reserve Club members from Reitz High School entertained at a sweater and sox hop Friday evening in the gym.
 
26 April 1943, Evansville (IN) Press, “Seniors Slash Activities to Suit War Time,” pg. 5, col. 1:
A “Sock Hop” in the Girls’ gym May 31, will inaugurate Senior activities followed on June 1 by the annual Senior-Faculty reception in the Boys’ gym.
   
23 May 1943, The Sunday Courier And Press (Evansville, IN), “Social Activities,” pg. 2-C, col. 1:
A “Sox-Hop” class party will be given in the girls gym, May 31 from 8:30 to 10:30 p.m.
 
24 October 1943, Chicago (IL) Daily Tribune, “War Bond Drive at Calumet to Buy Army Plane,” pt. 3, pg. 2, col. 4:
The Junior Red Cross is working on 100 hospital utility bags and hospital slippers, and at a recent sock hop, where dancers checked shoes to dance in socks, funds were raised for the Red Cross.
     
13 January 1944, Freeport (IL) Journal-Standard, pg. 5, col. 2:
“Sox Hop” To be Held
Jan. 28 Under Auspices
Of The Philomatheans
 
27 February 1944, The Sunday Star (Washington, DC), ‘American Junior Red Cross” by Philip H. Love, pg. C-6, col. 6:
A current junior fad is the “sock hop,” which raises money but, as the Red Cross’ Robert P. MacHatton points out, “saves wear and tear on shoe leather and the gymnasium floor.”
 
2 June 1944, Springfield (MA) Daily Republican, “Stafford Springs,” pg. 4, col. 6:
The freshman class will inaugurate a new kind of dance tomorrow night in the high school gym, the sock-hop so called, because no one will be allowed on the floor unless in stocking feet.
 
3 June 1944, Hartford (CT) Courant, “Students In Stafford Hold Shoeless Dance,” pg. 4, col. 5:
Stafford Springs, June 2.—(AP.)—About 100 shoeless coupled danced tonight in the Stafford Springs High School gymnasium as the freshman class staged a “sock hop.”
 
All shoes had to be checked at the door, and the freshmen was so intent upon obedience to the rule that even a newspaperman who dropped in to check on the event had to doff his footgear and shuffle around in socks.
 
It was the first “sock hop” in Stafford Springs and maybe in Connecticut, but the youngsters readily admitted it was not their idea. They’d seen a similar dance in a movie.
     
24 May 1947, Chicago (IL) Defender, pg. 21, col. 2:
Illinois State
DECATUR
Boy Scout Troop No. 34 and Girl Scout Troop No. 60 gave a “sox hop” party at the Longview Center.
 
OCLC WorldCat record
Sox Hop at Dana Junior High School in San Pedro remove shoes to prevent damaging floor of new gym, 1956
Author: Gray
Publisher: University of Southern California. Libraries 1956-01-03
Edition/Format:   Downloadable visual material : Graphic : English
Publication: Los Angeles Examiner Negatives Collection, 1950-1961
Summary:
9 images. Dana Junior High School in San Pedro remove shoes to prevent damaging floor of new gym, 3 January 1956. Judy Mendenhall; Elaine Panousis; Joyce Blankenburg; Tamara Lee; Ronnie Berglund; Charles Arreola; Julie Avila; Frank Stanovich; Pat Carter; Linda Schmalz.; Supplementary material reads: “Feature future—Att. Rib. Gershon. City Desk. Illus. Sox Hop. Students at Dana Junior High School, San Pedro, are proud of their new boys’ gymnasium and so to prevent damaging its highly polished floor they have inaugurated a ‘sox hop’. This is the weekly dance held during the noon recess with ninth graders only eligible. Both boys and girls must remove their shoes before entering the building. Boys place shoes against walls, girls in front of a bench at opposite end. Dancing is to records. 1-2: Off with the shoes and pay as you enter! Judy Mendenhall holds cigar box to receive dime from Elaine Panousis while Joyce blankenburg reaches down to take shoes and other girls crowd in doorway holding up shoes. 3: Girls put shoes on floor in front of bench to await dance partners. 4: Tamara Lee and Charles Arreola (left) and Ronnie Berglund and Bonnie Lane dancing. 5-6: Group dance. Note—no shoes. 7-8: Julie Avila and Frank Stanovich bee-hop while admiring fellow students clap hands to rhythm. 9: There’s alwaysmore girls than boys so Pat Carter and Linda Schmalz practice intricate steps. 10: Warning bell to resume classes ring and boys hurriedly don shoes they had lined up against wall”.
 
OCLC WorldCat record
El baile del calcetín = Sock hop : fox-swing
Author: Lynn Paul; Douglas.; Millet.
Publisher: [Madrid] Hispavox [1963]
Edition/Format:   Musical score : Spanish
 
OCLC WorldCat record
Aladdin’s rock ‘n roll sock hop.
Author: Thurston Harris; Calvin Boze; Lee Allen; Amos Milburn; Little Wilbur & the Pleasers.; All authors
Publisher: France : Liberty, [1982]
Edition/Format:   Music LP : English
 
OCLC WorldCat record
The best of 60s sock hop.
Publisher: Hollywood, CA : Priority Records, ℗1987.
Edition/Format:   Music CD : Cassette recording : CD audio : English
 
OCLC Worldcat record
60’s dance party : sock hop.
Author: Lesley Gore; Bobby Rydell; Chubby Checker; Del Shannon; Mary Wells; All authors
Publisher: St. Laurent, Quebec, Canada : Madacy Entertainment Group, ℗1997.
Edition/Format:   Music CD : CD audio : English
 
OCLC WorldCat record
The sock hop collection. Be my baby.
Author: Sam Cooke; Darlene Love; Elvis Presley; Neil Sedaka; Peggy March; All authors
Publisher: [Fairfax, VA] : Direct Holdings Americas, Inc., c2014.
Edition/Format:   Music CD : CD audio : English