The first tests were from the WHO. They were very inaccurate and gave many false positives and negatives. The US developed alternatives amazingly quickly. Production came in similar record setting time. The number of tests available and tests given have increased exponentially over the last handful of days.
Everything Ivecread says there was were major screwups by CDC and bureaucratic turf wars and obstacles out of CDC and FDA that slowed the rollout of testing in the US. This has been reported and well documented by media and commentators across the ideological spectrum. In fact , liberal media has been less forthcoming about these screwups because they reflect badly on federal bureaucrats and our regulatory regime