I am trying to find UTC offsets for datettimes. Some of those datetimes are prior to 1967 and those have some issues as different states adopted different daylight savings time options. The data that I have is the longitude and latitude and the date time. If I try to find the timezone then convert that to a UTC offset that might give a wrong result.

For Example:
Texas is part of America/Chicago Timezone but for years prior to 1967 Texas didn’t have DST while chicago did. So if i get the geo position of texas and get the timezone then convert to UTC offset I will get the wrong result because it will account for daylight savings time while there was none in texas.

Is there a library or a database that I can use for this?