Here is some information below.
Dear Ms. Carmichael,
Thank you for posting your request on History Hub!
We searched National Archives Catalog and located the World War II Operations Reports, 1940-1948 in the Records of the Adjutant General's Office, 1917-1985 (Record Group 407) that may include records for the 290th Infantry Regiment. The regiment was assigned to the 75th Infantry Division during World War II. For more information about these records, please contact the National Archives at College Park - Textual Reference (RDT2) via email at email@example.com. We were unable to locate specific records of Company L. Records of lower echelon units sometimes were incorporated into the files of the regiment.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RDT2. We apologize for this inconvenience and appreciate your understanding and patience.
An unofficial online version of the 290th Infantry Regiment’s combat diary is available at 290th Infantry Combat Diary.
We hope this is helpful. Best of luck with your research!