The phrase "was maintained" is correct and usable in written English. You can use it when expressing that something has been kept in the same state. For example, "The store's standard of excellence was maintained throughout the years."
But decorum was maintained.
Regional stability was maintained.
Order was maintained.
Blind was maintained.
But the peace was maintained.
Nothing was maintained or mended.
An extraordinary high standard was maintained throughout.
Compulsory chapel was maintained until 1926.
Ion source was maintained at 300 °C.
Perennial flow was maintained by large springs.
Temperature was maintained at 37 °C.
When I feel like I can't trust my brain 100%, Ludwig really comes in handy. It makes me translate and proofread faster and my output more reliable.
Claudia Letizia
Head Translator and Proofreader @ organictranslations.eu