After the war, Cammer returned to the firm of Witt & Cammer.
 (On November 24, 1947, the address for "Witt & Cammer, Esqs."
was 9 East 40th Street, New York, NY.)
 
During 1948, Pressman formed Pressman, Witt & Cammer.
Bella Abzug started her career there.


On August 20, 1948, Cammer represented Ware Group members Witt, Pressman, and John Abt before HUAC, less than a week before on the famous "Confrontation Day" hearing of HUAC in which Alger Hiss and Whittaker Chambers faced each other publicly for the first time.
Chambers described the day as follows:  
On August 10th, a trio of witnesses collectively more interesting than [Henry] Collins appeared before the Committee.
They were Lee Pressman, who had been a member of the Ware Group, Nathan Witt and John Abt, each of whom, in succession, had been its head.
Witt and Abt were now law partners in New York City.
Each was accompanied at his hearing by an attorney, Mr. Harold Cammer, a partner in the law firm of Nathan, Witt and Cammer.

The firm changed its name briefly to Pressman, Witt & Cammer after Lee Pressman joined in 1948, But Pressman became caught up in the Hiss Case.
HUAC began investigating Pressman and Witt (also a member of the group) and the stress began to wear Pressman down, even causing him to become paranoid to a degree.
Pressmen left the firm peremptorily in 1949.
Testifying again before HUAC in 1950, Pressman named Witt as a member of the CPUSA and the Ware group.
Cammer represented Witt and fellow attorney John Abt before HUAC in the 1950 hearings.

In 1951, Cammer joined more than half a dozen other lawyers in defending 17 Communist Party members, including Elizabeth Gurley Flynn.
 The communists were accused of charged conspiring to "teach and advocate violent overthrow" of the government.
 The other lawyers were: Abraham L. Pomerantz, Carol Weiss King, Victor Rabinowitz, Michael Begun, Mary Kaufman, Leonard Boudin, and Abraham Unger.
 Later, they were relieved by O. John Rogge, gangster Frank Costello's lawyer George Wolf, William W. Kleinman, Joseph L. Delaney, Frank Serri, Osmond K. Fraenkel, Henry G. Singer, Abraham J. Gellinoff, Raphael P. Koenig, and Nicholas Atlas.
After the war, Cammer returned to the firm of Witt & Cammer.  (On November 24, 1947, the address for "Witt & Cammer, Esqs." was 9 East 40th Street, New York, NY.)  
During 1948, Pressman formed Pressman, Witt & Cammer. Bella Abzug started her career there.

On August 20, 1948, Cammer represented Ware Group members Witt, Pressman, and John Abt before HUAC, less than a week before on the famous "Confrontation Day" hearing of HUAC in which Alger Hiss and Whittaker Chambers faced each other publicly for the first time. Chambers described the day as follows:  
On August 10th, a trio of witnesses collectively more interesting than [Henry] Collins appeared before the Committee. They were Lee Pressman, who had been a member of the Ware Group, Nathan Witt and John Abt, each of whom, in succession, had been its head. Witt and Abt were now law partners in New York City. Each was accompanied at his hearing by an attorney, Mr. Harold Cammer, a partner in the law firm of Nathan, Witt and Cammer.
The firm changed its name briefly to Pressman, Witt & Cammer after Lee Pressman joined in 1948, But Pressman became caught up in the Hiss Case. HUAC began investigating Pressman and Witt (also a member of the group) and the stress began to wear Pressman down, even causing him to become paranoid to a degree. Pressmen left the firm peremptorily in 1949. Testifying again before HUAC in 1950, Pressman named Witt as a member of the CPUSA and the Ware group. Cammer represented Witt and fellow attorney John Abt before HUAC in the 1950 hearings.
In 1951, Cammer joined more than half a dozen other lawyers in defending 17 Communist Party members, including Elizabeth Gurley Flynn.  The communists were accused of charged conspiring to "teach and advocate violent overthrow" of the government.  The other lawyers were: Abraham L. Pomerantz, Carol Weiss King, Victor Rabinowitz, Michael Begun, Mary Kaufman, Leonard Boudin, and Abraham Unger.  Later, they were relieved by O. John Rogge, gangster Frank Costello's lawyer George Wolf, William W. Kleinman, Joseph L. Delaney, Frank Serri, Osmond K. Fraenkel, Henry G. Singer, Abraham J. Gellinoff, Raphael P. Koenig, and Nicholas Atlas.
Harold I. Cammer