Final answer:
The U.S. District Court is generally considered to be the highest trial court in the federal judicial system.
Step-by-step explanation:
The highest trial court in the federal judicial system would generally be considered the U.S. District Court. This is the primary court where federal cases begin and where evidence is presented. Losing parties in these cases may then appeal to the U.S. Court of Appeals, and if necessary, to the U.S. Supreme Court.