Understanding Salesforce Field History Tracking on Record Creation

Default Field History Tracking Behavior on Record Creation

By default, field history tracking in Salesforce creates only one entry when a record is first created: the record creation event, which captures the user who created the record and the date and time of creation.
Field history entries for individually tracked fields are only created when field values are changed or modified after the record exists. Inputting a value into a tracked field during the initial record creation does not constitute a change and is therefore not captured in the history list.

Exception: Automation That Performs Data Manipulation Language (DML) Operations

If your organization has automation that runs on record creation — such as Apex, Flow, Process Builder, or Workflow Rules — and that automation performs Data Manipulation Language (DML) operations that write values into tracked fields, those field values will be included in the history entry for record creation.
This exception explains why some field values appear in the history list while others do not: fields updated by automation at record creation are captured; fields populated manually during the initial save are not.

Summary of Expected Outcomes

• Field values entered manually at record creation: not captured in field history
• Field values written by automation (Apex, Flow, Process Builder, Workflow) at record creation: captured in field history