Each month, the National Climatic Data Center provides an archive of one minute interval data from the ASOS sites in the United States. Unfortunately, the data format of this information is brutal to work with. Fortunately for you, the IEM processes this information and provides it for download here. The archive is available up until: 24 Feb 2024. There is a different interface to download the routine hourly observations from this network and for sites over the entire globe.
Updated 12 Oct 2023: The backend for this portal has been updated and a number of bugs / undefined behaviour has been fixed. My appologies if you had automation that was reliant on these quirks. Missing data is now represented by "M".