U.S. Half Fan Flat - Annin Style 85.
U.S. flag manufacturers have long made available not only bunting but actual flags which are striped in the national colors. These red-white-blue flags are sometimes plain, sometimes decorated with stars. This flag appears to be one such flag. Although the national flag of Thailand is similar, it would have been unlikely to have flown at the Star-Spangled Banner Flag House in Baltimore. Moreover, the Thai flag has a blue stripe double the width of any of the other stripes.